diff --git a/jsconfig.json b/jsconfig.json
index ddf88703..0820c537 100644
--- a/jsconfig.json
+++ b/jsconfig.json
@@ -5,10 +5,13 @@
     "allowJs": true,
     "strict": true,
     "noEmit": true,
-    "noImplicitAny": false,
+    "noImplicitAny": true,
+    "noImplicitThis": true,
     "noImplicitReturns": true,
     "noUnusedLocals": true,
     "noUnusedParameters": true,
+    "strictFunctionTypes": true,
+
     "lib": ["ES2022", "DOM"],
     // Treat all JS files as modules
     "moduleDetection": "force",
@@ -17,6 +20,6 @@
     "skipLibCheck": true,
     "target": "ESNext"
   },
-  "include": ["static/js/**/*.js"],
-  "exclude": ["static/js/vendors/**", "static/js/vendors/**/*.mjs"]
+  "include": ["static/js/**/*.js" ],
+  "exclude": ["static/js/vendors/**", "static/js/vendors/**/*.mjs", "static/js/vendors/**/*.js"  ]
 }
diff --git a/justfile b/justfile
index b630a1d2..4296eee6 100644
--- a/justfile
+++ b/justfile
@@ -59,6 +59,7 @@ front-fmt:
 
 front-lint:
     biome lint static/
+    tsc -p jsconfig.json
 
 # check CSS rules
 front-rules:
diff --git a/static/js/app/authSession.js b/static/js/app/authSession.js
index a1ef161e..68101541 100644
--- a/static/js/app/authSession.js
+++ b/static/js/app/authSession.js
@@ -8,6 +8,14 @@ import { updateStorageUsageDisplay } from './main.js';
 import { app } from './state.js';
 import { ui } from './ui.js';
 
+/**
+ * @import {User} from '../core/types.js'
+ */
+
+/**
+ *
+ * @returns {Promise<User | null>}
+ */
 async function refreshUserData() {
     const USER_DATA_KEY = 'oxicloud_user';
 
@@ -25,6 +33,7 @@ async function refreshUserData() {
             return null;
         }
 
+        /** @type {User} */
         const userData = await response.json();
         console.log('Refreshed user data from server:', userData);
         console.log('Storage from server: used=', userData.storage_used_bytes, 'quota=', userData.storage_quota_bytes);
@@ -83,6 +92,7 @@ async function checkAuthentication() {
         // Check session validity by calling /api/auth/me (cookie auto-sent)
         console.log('Checking session via /api/auth/me...');
 
+        /** @type {User} */
         const userData = JSON.parse(localStorage.getItem(USER_DATA_KEY) || '{}');
         if (userData.username) {
             // We have cached user data — render immediately, refresh in background
diff --git a/static/js/app/filesView.js b/static/js/app/filesView.js
index 9bc94db5..c8f01d7c 100644
--- a/static/js/app/filesView.js
+++ b/static/js/app/filesView.js
@@ -9,14 +9,14 @@ import { app } from './state.js';
 import { ui } from './ui.js';
 import { uiNotifications } from './uiNotifications.js';
 
-/** @import {FileInfo, FolderInfo} from '../core/types.js' */
+/** @import {FileItem, FolderItem} from '../core/types.js' */
 
 let isLoadingFiles = false;
 
 /**
  * getFolder information
  * @param {string} id the id of the folder
- * @returns {Promise<FolderInfo>}
+ * @returns {Promise<FolderItem>}
  */
 async function getFolder(id) {
     /** @type {HeadersInit} */
@@ -47,7 +47,7 @@ async function getFolder(id) {
 async function rebuildBreadCrumb() {
     /**
      * Store the leaf (this is the current displayed folder)
-     * @type {FolderInfo | null}
+     * @type {FolderItem | null}
      */
     let currentFolderInfo = null;
 
@@ -172,7 +172,11 @@ async function loadFiles(options = { insertHistory: true }) {
 
         if (forceRefresh) {
             url += `&force_refresh=true`;
-            if (requestOptions.headers) requestOptions.headers['X-Force-Refresh'] = 'true';
+            if (requestOptions.headers) {
+                const headers = new Headers(requestOptions.headers);
+                headers.set('X-Force-Refresh', 'true');
+                requestOptions.headers = headers;
+            }
             console.log('Forcing complete refresh ignoring cache');
         }
 
@@ -202,10 +206,10 @@ async function loadFiles(options = { insertHistory: true }) {
             multiSelect.init(); // this will wire buttons & select-all-checkbox
         }
 
-        /** @type {FolderInfo[]} */
+        /** @type {FolderItem[]} */
         const folderList = Array.isArray(listing.folders) ? listing.folders : [];
 
-        /** @type {FileInfo[]} */
+        /** @type {FileItem[]} */
         const fileList = Array.isArray(listing.files) ? listing.files : [];
 
         if (folderList.length === 0 && fileList.length === 0) {
diff --git a/static/js/app/main.js b/static/js/app/main.js
index 626980e9..8d9ce11e 100644
--- a/static/js/app/main.js
+++ b/static/js/app/main.js
@@ -35,6 +35,10 @@ import { loadTrashItems } from './trashView.js';
 import { ui } from './ui.js';
 import { setupUserMenu } from './userMenu.js';
 
+/**
+ * @import {User} from '../core/types.js'
+ */
+
 // Upload dropdown listener state (prevents accumulated listeners)
 /** @type {((e: MouseEvent) => void) | null} */
 let uploadDropdownDocumentClickHandler = null;
@@ -141,7 +145,7 @@ const ACTIONS_BAR_TEMPLATES = {
 
 /**
  *
- * @param {string} mode
+ * @param {'files' | 'trash' | 'favorites' | 'recent' | 'hidden'} mode
  * @param {boolean} [force=false]
  * @returns
  */
@@ -494,6 +498,7 @@ function setupEventListeners() {
     ui.setupDragAndDrop();
 
     // Debounce timer for live search
+    /** @type {ReturnType<typeof setTimeout>} */
     let searchDebounceTimer = null;
     const SEARCH_DEBOUNCE_MS = 300;
     const SEARCH_MIN_CHARS = 3;
@@ -726,7 +731,7 @@ export function selectFolder(id, name) {
 
 /**
  * Update the storage usage display with the user's actual storage usage
- * @param {Object} userData - The user data object
+ * @param {User} userData - The user data object
  */
 function updateStorageUsageDisplay(userData) {
     // Default values
diff --git a/static/js/app/navigation.js b/static/js/app/navigation.js
index 3bea519a..4cfba60f 100644
--- a/static/js/app/navigation.js
+++ b/static/js/app/navigation.js
@@ -136,12 +136,6 @@ export const SECTIONS_MAPPER = {
  */
 function setCurrentSection(section) {
     if (app.currentSection === section) return false;
-
-    // Set all view flags - true for active section, false for others
-    Object.entries(SECTIONS_MAPPER).forEach(([key, flag]) => {
-        app[flag] = key === section;
-    });
-
     app.currentSection = section;
 
     // Update nav item active classes by finding matching item from DOM
diff --git a/static/js/app/searchView.js b/static/js/app/searchView.js
index 1ae99d57..25a56d93 100644
--- a/static/js/app/searchView.js
+++ b/static/js/app/searchView.js
@@ -8,9 +8,14 @@ import { app } from './state.js';
 import { ui } from './ui.js';
 
 /**
- * @param {string} query
- * @param {string} [sortBy]
+ * @import {SearchCriteria, SortByEnnum} from '../core/types.js'
  */
+
+/**
+ * @param {string} query
+ * @param {SortByEnnum} [sortBy]
+ */
+// FIXME: refactor with search.js ?
 async function performSearch(query, sortBy) {
     console.log(`Performing search for: "${query}" (sort: ${sortBy || 'relevance'})`);
 
@@ -20,9 +25,11 @@ async function performSearch(query, sortBy) {
 
         ui.showError(`<h3><i class="fas fa-spinner fa-spin search-spinner"></i> Searching for "${query}"...</h3>`);
 
+        /** @type {SearchCriteria} */
         const options = {
             recursive: true,
             limit: 100,
+            offset: 0,
             sort_by: sortBy || 'relevance'
         };
 
@@ -51,7 +58,8 @@ document.addEventListener('search-resort', (e) => {
     const event = /** @type {CustomEvent<{sort_by: string}>} */ (e);
     const searchInput = /** @type {HTMLInputElement} */ (document.querySelector('.search-container input'));
     if (searchInput?.value.trim()) {
-        performSearch(searchInput.value.trim(), event.detail.sort_by);
+        const sortBy = /** @type {SortByEnnum} */ (event.detail.sort_by);
+        performSearch(searchInput.value.trim(), sortBy);
     }
 });
 
diff --git a/static/js/app/state.js b/static/js/app/state.js
index 06bc3da6..3d030c84 100644
--- a/static/js/app/state.js
+++ b/static/js/app/state.js
@@ -3,39 +3,70 @@
  * Centralized mutable state for app and cached DOM references.
  */
 
-/** @import {FolderInfo} from '../core/types.js' */
+/** @import {FileItem, FolderItem, LightItem} from '../core/types.js' */
 
 export const app = {
     currentView: 'grid',
 
     /** @type {string | null} */
     currentPath: '',
+
+    /** @type {string | null} */
     currentFolder: null,
 
-    /** @type {FolderInfo | null} */
+    /** @type {FolderItem | null} */
     currentFolderInfo: null,
 
-    /** @type {Object | null} */
+    /** @type {FolderItem | null} */
     contextMenuTargetFolder: null,
 
-    /** @type {Object | null} */
+    /** @type {FileItem | null} */
     contextMenuTargetFile: null,
     selectedTargetFolderId: '',
     moveDialogMode: 'file',
 
+    /** @type {string | null} */
+    moveDialogItemId: null,
+
+    /** @type {'file' | 'folder' | null} */
+    moveDialogItemMode: null,
+
+    /** @type {string | null} */
+    moveDialogCurrentFolderId: null,
+
+    /** @type {Array<{id: string, name: string}>} */
+    moveDialogBreadcrumb: [],
+
+    /** @type {FileItem[] | null} */
+    playlistDialogFiles: null,
+
     /** @type {String | null} */
     currentSection: null, // will be defined on first call
     isSearchMode: false,
+
+    /** @type {FileItem | FolderItem | null} */
     shareDialogItem: null,
+
+    /** @type {'file' | 'folder' | null} */
     shareDialogItemType: null,
+
+    /** @type {String | null} */
     notificationShareUrl: null,
+
+    /** @type {string | null} */
     userHomeFolderId: null,
+
+    /** @type {string | null} */
     userHomeFolderName: null,
-    /** @type {Object[]} */
+
+    /** @type {Array<{id: string, name: string}>} */
     breadcrumbPath: [], // Array of {id, name} tracking folder navigation hierarchy
 
     /** @type {String | null} */
-    viewFile: null // current file in inline view
+    viewFile: null, // current file in inline view
+
+    /** @type {LightItem[] | null} */
+    batchMoveItems: null
 };
 
 export const appElements = {
diff --git a/static/js/app/trashView.js b/static/js/app/trashView.js
index f69d8542..8d2517fb 100644
--- a/static/js/app/trashView.js
+++ b/static/js/app/trashView.js
@@ -9,6 +9,11 @@ import { multiSelect } from '../features/files/multiSelect.js';
 import { appElements } from './state.js';
 import { ui } from './ui.js';
 
+/**
+ *
+ * @import {TrashItem} from '../core/types.js'
+ */
+
 async function loadTrashItems() {
     const elements = appElements;
 
@@ -25,7 +30,7 @@ async function loadTrashItems() {
             </div>
         `;
 
-        ui.updateBreadcrumb('');
+        ui.updateBreadcrumb();
 
         const trashItems = await fileOps.getTrashItems();
 
@@ -46,6 +51,10 @@ async function loadTrashItems() {
     }
 }
 
+/**
+ *
+ * @param {TrashItem} item
+ */
 function addTrashItemToView(item) {
     const elements = appElements;
     const isFile = item.item_type === 'file';
diff --git a/static/js/app/ui.js b/static/js/app/ui.js
index 52bf89f9..3e472373 100644
--- a/static/js/app/ui.js
+++ b/static/js/app/ui.js
@@ -25,10 +25,17 @@ import { app } from './state.js';
 import { uiFileTypes } from './uiFileTypes.js';
 import { uiNotifications } from './uiNotifications.js';
 
+/**
+ *  @import {FileItem, FolderItem} from '../core/types.js'
+ *  @import {BatchResult} from '../features/files/fileOperations.js'
+ */
+
 // UI Module
 const ui = {
-    /** @type {HTMLDListElement | null} */
-    //dragPreview,
+    /** @type {HTMLDivElement | null} */
+    dragPreview: null,
+    /** @type {HTMLDivElement | null} */
+    draggedItems: null,
 
     /**
      * Initialize context menus and dialogs
@@ -338,21 +345,31 @@ const ui = {
 
         const dropzone = document.getElementById('dropzone');
 
+        /**
+         *
+         * @param {DataTransfer} dataTransfer
+         * @returns {Promise<any[]|null>}
+         */
         const collectDroppedEntries = async (dataTransfer) => {
             const items = Array.from(dataTransfer?.items || []);
             const rootEntries = items.map((it) => (typeof it.webkitGetAsEntry === 'function' ? it.webkitGetAsEntry() : null)).filter(Boolean);
 
             if (rootEntries.length === 0) return null;
 
+            /** @type {Array<{file: File, relativePath: string}>} */
             const out = [];
 
+            /**
+             * @param {FileSystemEntry} entry
+             * @param {string} prefix
+             */
             const walkEntry = async (entry, prefix = '') => {
                 if (!entry) return;
 
                 if (entry.isFile) {
                     await new Promise((resolve) => {
-                        entry.file(
-                            (file) => {
+                        /** @type {FileSystemFileEntry} */ (entry).file(
+                            (/** @type {File} */ file) => {
                                 out.push({ file, relativePath: `${prefix}${file.name}` });
                                 resolve(undefined);
                             },
@@ -364,7 +381,7 @@ const ui = {
 
                 if (entry.isDirectory) {
                     const dirPrefix = `${prefix}${entry.name}/`;
-                    const reader = entry.createReader();
+                    const reader = /** @type {FileSystemDirectoryEntry} */ (entry).createReader();
 
                     while (true) {
                         const children = await new Promise((resolve) => {
@@ -636,7 +653,7 @@ const ui = {
 
     /**
      * Check if a file can be previewed in the viewer
-     * @param {Object} file - File object with mime_type property
+     * @param {FileItem} file
      * @returns {boolean}
      */
     isViewableFile(file) {
@@ -647,6 +664,7 @@ const ui = {
      * Get FontAwesome icon class for a filename based on its extension.
      * Used as fallback when the backend DTO doesn't include icon_class
      * (e.g. trash items).
+     * @param {string} fileName
      */
     getIconClass(fileName) {
         return uiFileTypes.getIconClass(fileName);
@@ -655,6 +673,7 @@ const ui = {
     /**
      * Get CSS special class for icon styling based on filename extension.
      * Used as fallback when the backend DTO doesn't include icon_special_class.
+     * @param {string} fileName
      */
     getIconSpecialClass(fileName) {
         return uiFileTypes.getIconSpecialClass(fileName);
@@ -695,13 +714,13 @@ const ui = {
      *  Data store + event delegation (replaces per-item listeners)
      * ================================================================ */
 
-    /** @type {Map<string, Object>} item data keyed by id */
+    /** @type {Map<string, FolderItem | FileItem>} item data keyed by id */
     _items: new Map(),
 
-    /** @type {Array<Object>} last rendered folder dataset */
+    /** @type {FolderItem[]} last rendered folder dataset */
     _lastFolders: [],
 
-    /** @type {Array<Object>} last rendered file dataset */
+    /** @type {FileItem[]} last rendered file dataset */
     _lastFiles: [],
 
     /** @type {boolean} */
@@ -716,9 +735,7 @@ const ui = {
     },
 
     /**
-     *
-     * @param {Object[]} folders
-     * @returns
+     * @param {FolderItem[]} folders
      */
     _renderFoldersToView(folders) {
         if (!Array.isArray(folders) || folders.length === 0) return;
@@ -733,9 +750,7 @@ const ui = {
     },
 
     /**
-     *
-     * @param {Object[]} files
-     * @returns
+     * @param {FileItem[]} files
      */
     _renderFilesToView(files) {
         if (!Array.isArray(files) || files.length === 0) return;
@@ -749,6 +764,10 @@ const ui = {
         target.appendChild(frag);
     },
 
+    /**
+     * @param {any[]} arr
+     * @param {any} item
+     */
     _upsertById(arr, item) {
         if (!Array.isArray(arr) || !item?.id) return;
         const idx = arr.findIndex((x) => x && x.id === item.id);
@@ -796,6 +815,7 @@ const ui = {
             await fileOps.moveFile(sourceId, targetFolderId);
         */
 
+        /** @type {BatchResult} */
         let result;
         switch (action) {
             case 'copy':
@@ -843,6 +863,7 @@ const ui = {
         this._delegationReady = true;
 
         // ── helpers ────────────────────────────────────────────────
+        /** @param {HTMLDivElement} card */
         const itemInfo = (card) => {
             if (!card) return null;
             const fileId = card.dataset.fileId;
@@ -864,6 +885,7 @@ const ui = {
             return null;
         };
 
+        /** @param {FileItem} file */
         const openFile = async (file) => {
             if (!file) return;
             if (recent) {
@@ -897,6 +919,7 @@ const ui = {
             }
         };
 
+        /** @param {HTMLElement} card */
         const navigateFolder = (card) => {
             const folderId = card.dataset.folderId;
             const folderName = card.dataset.folderName;
@@ -912,27 +935,31 @@ const ui = {
             loadFiles();
         };
 
+        /**
+         * @param {HTMLElement} card
+         * @param {{ type: string, id: string, name: string | undefined, data: FolderItem | FileItem | undefined }} info
+         */
         const setContextTarget = (card, info) => {
             if (info.type === 'folder') {
-                app.contextMenuTargetFolder = {
+                app.contextMenuTargetFolder = /** @type {FolderItem} */ ({
                     id: info.id,
                     name: card.dataset.folderName,
                     parent_id: card.dataset.parentId || ''
-                };
+                });
             } else {
-                const fileData = info.data || this._items.get(info.id);
-                app.contextMenuTargetFile = {
+                const fileData = /** @type {FileItem | undefined} */ (info.data || this._items.get(info.id));
+                app.contextMenuTargetFile = /** @type {FileItem} */ ({
                     id: info.id,
                     name: card.dataset.fileName,
                     folder_id: card.dataset.folderId || '',
                     mime_type: fileData?.mime_type || null
-                };
+                });
             }
         };
 
         // ──  click (open / navigate; select only via checkbox) ──
         filesList.addEventListener('click', (e) => {
-            const card = /** @type {HTMLElement} */ (e.target).closest('.file-item');
+            const card = /** @type {HTMLDivElement | null} */ (/** @type {HTMLElement} */ (e.target).closest('.file-item'));
             if (!card) return;
 
             if (/** @type {HTMLElement} */ (e.target).closest('.file-actions')) {
@@ -975,7 +1002,7 @@ const ui = {
             if (info.type === 'folder') {
                 navigateFolder(card);
             } else {
-                openFile(info.data);
+                openFile(/** @type {FileItem} */ (info.data));
             }
         });
 
@@ -989,7 +1016,7 @@ const ui = {
         // ── shared events ──────────────────────
 
         filesList.addEventListener('contextmenu', (e) => {
-            const card = /** @type {HTMLElement} */ (e.target).closest('.file-item');
+            const card = /** @type {HTMLDivElement | null} */ (/** @type {HTMLElement} */ (e.target).closest('.file-item'));
             if (!card) return;
             e.preventDefault();
             const info = itemInfo(card);
@@ -1008,7 +1035,7 @@ const ui = {
 
         // dragstart
         filesList.addEventListener('dragstart', (e) => {
-            const card = /** @type {HTMLElement} */ (e.target).closest('.file-item');
+            const card = /** @type {HTMLDivElement | null} */ (/** @type {HTMLElement} */ (e.target).closest('.file-item'));
             if (!card) {
                 e.preventDefault();
                 return;
@@ -1088,9 +1115,11 @@ const ui = {
                 // TODO better naming like ("selection in ${parent.name}") modulo i18n ? ...
                 const now = new Date().toISOString().replace(/T/, ' ').replace(/\.*/, '').replaceAll(/:/g, '-');
                 nameEncoded = `oxicloud ${now}.zip`;
+                /** @type {string[]} */
                 const folders = [];
+                /** @type {string[]} */
                 const files = [];
-                filesList.querySelectorAll(`div.selected`).forEach((e) => {
+                /** @type {NodeListOf<HTMLDivElement>} */ (filesList.querySelectorAll(`div.selected`)).forEach((e) => {
                     const item = itemInfo(e);
                     if (item.type === 'file') {
                         files.push(item.id);
@@ -1164,6 +1193,7 @@ const ui = {
      *  Favorite star helper – attaches a direct click handler to a
      *  star <button> so the event never bubbles to the card.
      * ================================================================ */
+    /** @param {HTMLElement} el */
     _bindStarClick(el) {
         const star = el.querySelector('.favorite-star');
         star?.addEventListener('click', (e) => {
@@ -1174,7 +1204,8 @@ const ui = {
             if (!favorites) return;
 
             // FIXME: make a function
-            const itemElement = shared?.closest('.file-item');
+            const itemElement = /** @type {HTMLElement | null} */ (shared?.closest('.file-item'));
+            if (!itemElement) return;
 
             const itemId = itemElement.dataset.fileId ? itemElement.dataset.fileId : itemElement.dataset.folderId;
             const itemType = itemElement.dataset.fileId ? 'file' : 'folder';
@@ -1187,7 +1218,7 @@ const ui = {
                 favorites.removeFromFavorites(itemId, itemType);
             } else {
                 this.setFavoriteVisualState(itemId, itemType, true);
-                favorites.addToFavorites(itemId, itemName, itemType);
+                favorites.addToFavorites(itemId, itemName, itemType, null);
             }
 
             // Keep context-menu label in sync if available
@@ -1201,26 +1232,30 @@ const ui = {
             e.preventDefault();
 
             // FIXME: make a function
-            const itemElement = shared?.closest('.file-item');
+            const itemElement = /** @type {HTMLElement | null} */ (shared?.closest('.file-item'));
+            if (!itemElement) return;
 
             const itemId = itemElement.dataset.fileId ? itemElement.dataset.fileId : itemElement.dataset.folderId;
             const itemType = itemElement.dataset.fileId ? 'file' : 'folder';
             const itemName = itemElement.dataset.fileId ? itemElement.dataset.fileName : itemElement.dataset.folderName;
 
             // TODO corrently dirty
-            const item = {
+            const item = /** @type {unknown} */ ({
                 id: itemId,
                 item_id: itemId,
                 item_type: itemType,
                 item_name: itemName
-            };
+            });
 
-            contextMenus.showShareDialog(item, itemType);
+            contextMenus.showShareDialog(/** @type {FileItem} */ (item), itemType);
         });
     },
 
     /**
      * Sync favorite visuals for a file/folder across grid and list views.
+     * @param {string} itemId
+     * @param {string} itemType
+     * @param {boolean} isFavorite
      */
     setFavoriteVisualState(itemId, itemType, isFavorite) {
         const selector = itemType === 'folder' ? `#files-list .file-item[data-folder-id="${itemId}"]` : `#files-list .file-item[data-file-id="${itemId}"]`;
@@ -1258,6 +1293,11 @@ const ui = {
         }
     },
 
+    /**
+     * @param {string} itemId
+     * @param {string} itemType
+     * @param {boolean} isShared
+     */
     setSharedVisualState(itemId, itemType, isShared) {
         console.log(`setSharedVisual call for ${itemId} ${itemType} to ${isShared}`);
         const selector = itemType === 'folder' ? `#files-list .file-item[data-folder-id="${itemId}"]` : `#files-list .file-item[data-file-id="${itemId}"]`;
@@ -1273,7 +1313,10 @@ const ui = {
      *  Element-creation helpers
      * ================================================================ */
 
-    /** Create a list row for a folder */
+    /**
+     * Create a list row for a folder
+     * @param {FolderItem} folder
+     */
     _createFolderItem(folder) {
         const el = document.createElement('div');
         el.className = 'file-item';
@@ -1314,7 +1357,10 @@ const ui = {
         return el;
     },
 
-    /** Create a grid card for a file */
+    /**
+     * Create a grid card for a file
+     * @param {FileItem} file
+     */
     _createFileItem(file) {
         const iconClass = file.icon_class || this.getIconClass(file.name);
         const iconSpecialClass = file.icon_special_class || this.getIconSpecialClass(file.name);
@@ -1425,7 +1471,7 @@ const ui = {
      * Render an array of folders into both grid and list views
      * using DocumentFragment for minimal reflows.
      *
-     * @param {FolderInfo[]} folders
+     * @param {FolderItem[]} folders
      */
     renderFolders(folders) {
         if (!this._delegationReady) this.initDelegation();
@@ -1442,6 +1488,7 @@ const ui = {
     /**
      * Render an array of files into both grid and list views
      * using DocumentFragment for minimal reflows.
+     * @param {FileItem[]} files
      */
     renderFiles(files) {
         if (!this._delegationReady) this.initDelegation();
@@ -1461,7 +1508,7 @@ const ui = {
 
     /**
      * Add a single folder to the active view.
-     * @param {Object} folder - Folder object
+     * @param {FolderItem} folder
      */
     addFolderToView(folder) {
         if (!this._delegationReady) this.initDelegation();
@@ -1479,7 +1526,7 @@ const ui = {
 
     /**
      * Add a single file to the active view.
-     * @param {Object} file - File object
+     * @param {FileItem} file
      */
     addFileToView(file) {
         if (!this._delegationReady) this.initDelegation();
@@ -1501,6 +1548,8 @@ const ui = {
 /**
  * Toggle selection state of a file/folder card.
  * Routes through the multiSelect module so batch actions know about selected items.
+ * @param {HTMLDivElement} card
+ * @param {MouseEvent} event
  */
 function toggleCardSelection(card, event) {
     if (multiSelect) {
@@ -1512,6 +1561,8 @@ function toggleCardSelection(card, event) {
 
 /**
  * Show the context menu anchored next to a trigger element (the 3-dot button).
+ * @param {HTMLElement} triggerElement
+ * @param {string} menuId
  */
 function showContextMenuAtElement(triggerElement, menuId) {
     // Hide any open menus first
@@ -1542,8 +1593,6 @@ function showContextMenuAtElement(triggerElement, menuId) {
     menu.classList.remove('hidden');
 }
 
-let __rubberBandJustFinished = false;
-
 /**
  * Rubber band (lasso) selection — click + drag on empty grid area
  * to draw a rectangle and select all cards it touches.
@@ -1567,16 +1616,18 @@ function initRubberBandSelection() {
     if (!container) return;
 
     container.addEventListener('mousedown', (e) => {
+        if (!(e instanceof MouseEvent)) return;
         // Only start if clicking empty area (not on a card, button, menu, input…)
         if (e.button !== 0) return; // left click only
+        const target = /** @type {Element} */ (e.target);
         if (
-            e.target.closest('.file-item') ||
-            e.target.closest('.context-menu') ||
-            e.target.closest('.upload-dropdown') ||
-            e.target.closest('button') ||
-            e.target.closest('input') ||
-            e.target.closest('.breadcrumb') ||
-            e.target.closest('.list-header')
+            target.closest('.file-item') ||
+            target.closest('.context-menu') ||
+            target.closest('.upload-dropdown') ||
+            target.closest('button') ||
+            target.closest('input') ||
+            target.closest('.breadcrumb') ||
+            target.closest('.list-header')
         )
             return;
 
@@ -1627,14 +1678,14 @@ function initRubberBandSelection() {
 
                 // Sync with multiSelect module
                 if (multiSelect) {
-                    const info = multiSelect._extractInfo(card);
+                    const info = multiSelect._extractInfo(/** @type {HTMLDivElement} */ (card));
                     if (info) multiSelect.select(info.id, info.name, info.type, info.parentId);
                 }
             } else {
                 card.classList.remove('selected');
                 // Deselect from multiSelect module
                 if (multiSelect) {
-                    const info = multiSelect._extractInfo(card);
+                    const info = multiSelect._extractInfo(/** @type {HTMLDivElement} */ (card));
                     if (info) multiSelect.deselect(info.id);
                 }
             }
@@ -1651,10 +1702,7 @@ function initRubberBandSelection() {
         // Suppress the click event that follows mouseup so the global
         // deselect handler doesn't immediately clear the selection.
         if (hadSelection) {
-            __rubberBandJustFinished = true;
-            requestAnimationFrame(() => {
-                __rubberBandJustFinished = false;
-            });
+            requestAnimationFrame(() => {});
         }
     });
 }
@@ -1709,6 +1757,7 @@ function showConfirmDialog({ title, message, confirmText, cancelText, danger = t
             overlay.classList.add('active');
         });
 
+        /** @param {boolean} result */
         const cleanup = (result) => {
             overlay.classList.remove('active');
             setTimeout(() => overlay.remove(), 200);
diff --git a/static/js/app/uiFileTypes.js b/static/js/app/uiFileTypes.js
index 497dc462..7d610c66 100644
--- a/static/js/app/uiFileTypes.js
+++ b/static/js/app/uiFileTypes.js
@@ -5,7 +5,7 @@
 
 import { isTextViewable } from '../core/formatters.js';
 
-/** @import {FileInfo} from '../core/types.js' */
+/** @import {FileItem} from '../core/types.js' */
 
 /** @type {Record<string, string>} */
 const ICON_CLASS_MAP = {
@@ -158,7 +158,7 @@ const uiFileTypes = {
     // TODO: 'd better to use a canViw() method in inlineViewer
     /**
      *
-     * @param {FileInfo} file
+     * @param {FileItem} file
      * @returns {boolean}
      */
     isViewableFile(file) {
diff --git a/static/js/core/csrf.js b/static/js/core/csrf.js
index b449c277..9756e356 100644
--- a/static/js/core/csrf.js
+++ b/static/js/core/csrf.js
@@ -18,6 +18,10 @@ function getCsrfToken() {
     return match ? match.split('=')[1] : '';
 }
 
+/**
+ * returns headers to add, this includes the X-CSRF-Token
+ * @returns {Record<String, String>}
+ */
 function getCsrfHeaders() {
     const token = getCsrfToken();
     return token ? { 'X-CSRF-Token': token } : {};
diff --git a/static/js/core/fetchWrapper.js b/static/js/core/fetchWrapper.js
index ded0840a..b2f67d56 100644
--- a/static/js/core/fetchWrapper.js
+++ b/static/js/core/fetchWrapper.js
@@ -37,6 +37,7 @@ const WRAPPER_USER_DATA_KEY = 'oxicloud_user';
 let _originalFetch = window.fetch.bind(window);
 
 /** Deduplicates concurrent refresh attempts into a single in-flight promise. */
+/** @type {Promise<boolean> | null} */
 let _refreshInFlight = null;
 
 async function _refresh() {
diff --git a/static/js/core/formatters.js b/static/js/core/formatters.js
index e24d99d6..2263c436 100644
--- a/static/js/core/formatters.js
+++ b/static/js/core/formatters.js
@@ -1,6 +1,7 @@
 /**
  * OxiCloud - Shared format and escaping utilities
  * Centralized global helpers for date/size/text formatting and XSS-safe escaping.
+ * Contains also checkers
  */
 
 /**
@@ -97,4 +98,13 @@ function isTextViewable(mimeType) {
     return TEXT_TYPES.includes(mimeType);
 }
 
-export { escapeHtml, formatDateShort, formatDateTime, formatFileSize, formatQuotaSize, isTextViewable };
+/**
+ * Chekif an email is valid
+ * @param {string} email
+ * @returns boolean
+ */
+function isEmailValid(email) {
+    return /^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(email);
+}
+
+export { escapeHtml, formatDateShort, formatDateTime, formatFileSize, formatQuotaSize, isEmailValid, isTextViewable };
diff --git a/static/js/core/i18n.js b/static/js/core/i18n.js
index 326574e6..108a838f 100644
--- a/static/js/core/i18n.js
+++ b/static/js/core/i18n.js
@@ -37,7 +37,7 @@ function resolveBrowserLocale() {
 let currentLocale = resolveBrowserLocale();
 
 // Cache for translations
-/** @type {Record<string, Object>} */
+/** @type {Record<string, any>} */
 const translations = {};
 
 /**
@@ -71,7 +71,7 @@ async function loadTranslations(locale) {
 
 /**
  * Get a nested translation value
- * @param {object} obj - The translations object
+ * @param {Record<string, any>} obj - The translations object
  * @param {string} path - The dot-notation path to the translation
  * @returns {string|null} - The translation value or null if not found
  */
@@ -110,7 +110,7 @@ function getNestedValue(obj, path) {
 /**
  * Replace parameters in a translation string
  * @param {string} text - The translation string with placeholders
- * @param {object} params - The parameters to replace
+ * @param {Record<string, any>} params - The parameters to replace
  * @returns {string} - The interpolated string
  */
 function interpolate(text, params) {
@@ -244,11 +244,19 @@ document.addEventListener('DOMContentLoaded', async () => {
 
 // Self-contained t wrapper — does NOT call the global t() because other
 // scripts (e.g. admin.js) may shadow it, which would cause infinite recursion.
-function safeT(key, params = {}) {
+/**
+ * @param {string} key
+ * @param {string | Record<string, any>} [paramsOrFallback] - interpolation params object, or a string fallback used when the key is missing
+ * @returns {string}
+ */
+function safeT(key, paramsOrFallback = {}) {
+    const fallback = typeof paramsOrFallback === 'string' ? paramsOrFallback : null;
+    const params = typeof paramsOrFallback === 'object' ? paramsOrFallback : {};
+
     const localeData = translations[currentLocale];
     if (!localeData) {
-        // Translations not loaded yet — return humanised key suffix
-        return key.split('.').pop() || key;
+        // Translations not loaded yet — return fallback or humanised key suffix
+        return fallback ?? key.split('.').pop() ?? key;
     }
 
     let value = getNestedValue(localeData, key);
@@ -258,7 +266,7 @@ function safeT(key, params = {}) {
         value = getNestedValue(translations.en, key);
     }
 
-    if (!value) return key;
+    if (!value) return fallback ?? key;
     return interpolate(value, params);
 }
 
diff --git a/static/js/core/icons.js b/static/js/core/icons.js
index 0d4c3ea2..12d6441d 100644
--- a/static/js/core/icons.js
+++ b/static/js/core/icons.js
@@ -15,6 +15,7 @@
 // All icons use viewBox="0 0 {width} 512" and fill="currentColor".
 // Keys use FA5 class names (without "fa-" prefix) for backward compatibility.
 
+/** @type {Record<String, Array<number | String>>} */
 const OxiIcons = {
     'arrow-left': [
         448,
@@ -503,7 +504,7 @@ function replaceIconsInElement(container) {
 
         const path = document.createElementNS('http://www.w3.org/2000/svg', 'path');
         path.setAttribute('fill', 'currentColor');
-        path.setAttribute('d', d);
+        path.setAttribute('d', /** @type {string} */ (d));
         svg.appendChild(path);
 
         el.replaceWith(svg);
diff --git a/static/js/core/languageSelector.js b/static/js/core/languageSelector.js
index cbc4c565..6c4bade5 100644
--- a/static/js/core/languageSelector.js
+++ b/static/js/core/languageSelector.js
@@ -34,6 +34,10 @@ function getAvailableLanguages() {
 const rtlLanguages = ['fa', 'ar'];
 
 // Update HTML lang attribute and dir for RTL languages
+/**
+ *
+ * @param {string} langCode
+ */
 function updateHtmlAttributes(langCode) {
     const htmlElement = document.documentElement;
 
@@ -150,6 +154,7 @@ function createLanguageSelector(containerId = 'language-selector') {
 
 /**
  * Toggle dropdown open/closed
+ * @param {HTMLElement} container
  */
 function toggleDropdown(container) {
     const isOpen = container.classList.contains('open');
@@ -162,6 +167,7 @@ function toggleDropdown(container) {
 
 /**
  * Open dropdown
+ * @param {HTMLElement} container
  */
 function openDropdown(container) {
     container.classList.add('open');
@@ -173,6 +179,7 @@ function openDropdown(container) {
 
 /**
  * Close dropdown
+ * @param {HTMLElement} container
  */
 function closeDropdown(container) {
     container.classList.remove('open');
@@ -184,6 +191,8 @@ function closeDropdown(container) {
 
 /**
  * Select a language
+ * @param {String} langCode
+ * @param {HTMLElement} container
  */
 async function selectLanguage(langCode, container) {
     await i18n.setLocale(langCode);
@@ -197,6 +206,8 @@ async function selectLanguage(langCode, container) {
 
 /**
  * Update the UI to reflect selected language
+ * @param {String} langCode
+ * @param {HTMLElement} container
  */
 function updateSelectedLanguage(langCode, container) {
     const languages = getAvailableLanguages();
@@ -213,7 +224,7 @@ function updateSelectedLanguage(langCode, container) {
     options.forEach((option) => {
         const isActive = option.getAttribute('data-lang') === langCode;
         option.classList.toggle('active', isActive);
-        option.setAttribute('aria-selected', isActive);
+        option.setAttribute('aria-selected', String(isActive));
     });
 }
 
diff --git a/static/js/core/modal.js b/static/js/core/modal.js
index 02770c31..369c4f61 100644
--- a/static/js/core/modal.js
+++ b/static/js/core/modal.js
@@ -10,25 +10,25 @@ const Modal = {
     // Modal element references
     /** @private @type {HTMLElement | null} */
     overlay: null,
-    // FIXME: unused ?
-    container: null,
     /** @private @type {HTMLElement | null} */
     icon: null,
     /** @private @type {HTMLElement | null} */
     title: null,
     /** @private @type {HTMLElement | null} */
     label: null,
-    /** @private @type {HTMLElement | null} */
+    /** @private @type {HTMLInputElement | null} */
     input: null,
-    /** @private @type {HTMLElement | null} */
+    /** @private @type {HTMLButtonElement | null} */
     cancelBtn: null,
-    /** @private @type {HTMLElement | null} */
+    /** @private @type {HTMLButtonElement | null} */
     confirmBtn: null,
-    /** @private @type {HTMLElement | null} */
+    /** @private @type {HTMLButtonElement | null} */
     closeBtn: null,
 
     // Current callback
+    /** @private @type {Function | null} */
     onConfirm: null,
+    /** @private @type {Function | null} */
     onCancel: null,
 
     /** @private @type {((value: string) => Promise<void>) | null} */
@@ -53,10 +53,10 @@ const Modal = {
         this.icon = document.getElementById('modal-icon');
         this.title = document.getElementById('modal-title');
         this.label = document.getElementById('modal-label');
-        this.input = document.getElementById('modal-input');
-        this.cancelBtn = document.getElementById('modal-cancel-btn');
-        this.confirmBtn = document.getElementById('modal-confirm-btn');
-        this.closeBtn = document.getElementById('modal-close-btn');
+        this.input = /** @type {HTMLInputElement} */ (document.getElementById('modal-input'));
+        this.cancelBtn = /** @type {HTMLButtonElement} */ (document.getElementById('modal-cancel-btn'));
+        this.confirmBtn = /** @type {HTMLButtonElement} */ (document.getElementById('modal-confirm-btn'));
+        this.closeBtn = /** @type {HTMLButtonElement} */ (document.getElementById('modal-close-btn'));
 
         // Event listeners
         this.errorEl = document.getElementById('modal-error');
@@ -106,13 +106,13 @@ const Modal = {
     /**
      * Show input modal (replacement for prompt())
      * @param {Object} options - Modal configuration
-     * @param {string} options.title - Modal title
-     * @param {string} options.label - Input label
-     * @param {string} options.placeholder - Input placeholder
-     * @param {string} options.value - Initial input value
-     * @param {string} options.icon - Font Awesome icon class (e.g., 'fa-folder-plus')
-     * @param {string} options.confirmText - Confirm button text
-     * @param {string} options.cancelText - Cancel button text
+     * @param {string} [options.title] - Modal title
+     * @param {string} [options.label] - Input label
+     * @param {string} [options.placeholder] - Input placeholder
+     * @param {string} [options.value] - Initial input value
+     * @param {string} [options.icon] - Font Awesome icon class (e.g., 'fa-folder-plus')
+     * @param {string} [options.confirmText] - Confirm button text
+     * @param {string} [options.cancelText] - Cancel button text
      * @param {(value: string) => Promise<void>} [options.action] - Async action called on confirm.
      *   Throw an Error to keep the modal open and display the error message inline.
      *   When omitted the modal resolves immediately with the input value (legacy behaviour).
@@ -292,7 +292,7 @@ const Modal = {
             if (this.onConfirm) this.onConfirm();
             this.close(true);
         } catch (e) {
-            this.showError(e.message || 'An error occurred');
+            this.showError(/** @type {Error} */ (e).message || 'An error occurred');
             this.confirmBtn.disabled = false;
             this.input.focus();
         }
diff --git a/static/js/core/notifications.js b/static/js/core/notifications.js
index 5d46d767..61019c10 100644
--- a/static/js/core/notifications.js
+++ b/static/js/core/notifications.js
@@ -15,13 +15,28 @@ import { i18n } from './i18n.js';
  *   clear()
  */
 
+/**
+ * @typedef {Object} BatchNotification
+ * @property {HTMLElement} el
+ * @property {Number} totalFiles,
+ * @property {Number} completed
+ * @property {Number} successCount
+ * @property {Number} errorCount
+ * @property {Number} lastLabelUpdateTs
+ * @property {String} lastLabelFile
+ */
+
 const notifications = (() => {
     /* ── state ──────────────────────────────────────────────── */
     let _badgeCount = 0;
     let _batchSeq = 0;
-    const _batches = {}; // batchId → { el, files:{}, totalFiles }
+
+    /** @type {Record<String,BatchNotification>} */
+    const _batches = {};
 
     /* ── DOM refs (resolved lazily) ─────────────────────────── */
+
+    /** @type {(id: string) => HTMLElement | null } */
     const $ = (id) => document.getElementById(id);
 
     /* ── bell toggle ────────────────────────────────────────── */
@@ -237,6 +252,8 @@ const notifications = (() => {
     /**
      * Mark a file as completed within a batch (updates overall bar).
      * DOM updates are throttled to every 5 files to avoid reflow starvation.
+     * @param {string} batchId
+     * @param {boolean} success
      */
     function fileCompleted(batchId, success) {
         const batch = _batches[batchId];
@@ -262,6 +279,9 @@ const notifications = (() => {
 
     /**
      * Finalise a batch – update icon and title.
+     * @param {string} batchId
+     * @param {number} successCount
+     * @param {number} totalFiles
      */
     function finishBatch(batchId, successCount, totalFiles) {
         const batch = _batches[batchId];
@@ -320,6 +340,10 @@ const notifications = (() => {
     }
 
     /* ── util ───────────────────────────────────────────────── */
+    // FIXME move to global library
+    /**
+     * @param {string} s
+     */
     function _esc(s) {
         const d = document.createElement('div');
         d.textContent = s;
diff --git a/static/js/core/types.js b/static/js/core/types.js
index 4d51f773..c02fb4c8 100644
--- a/static/js/core/types.js
+++ b/static/js/core/types.js
@@ -1,5 +1,19 @@
 /**
- * @typedef {Object} FolderInfo
+ * @typedef {'file' | 'folder'} ItemTypeEnum
+ */
+
+// FIXME to simplify
+/**
+ * @typedef {Object} LightItem
+ * @property {string} id
+ * @property {string} name
+ * @property {ItemTypeEnum} type
+ * @property {string} parentId
+ */
+
+//FIXME: rename into FolderItem
+/**
+ * @typedef {Object} FolderItem
  * @property {string} category
  * @property {number} created_at - timestamp
  * @property {string} icon_class
@@ -13,8 +27,9 @@
  * @property {string} path the full path
  */
 
+//FIXME: rename into FileItem
 /**
- * @typedef {Object} FileInfo
+ * @typedef {Object} FileItem
  * @property {string} category
  * @property {number} created_at - timestamp
  * @property {string} icon_class
@@ -39,7 +54,7 @@
  */
 
 /**
- * @typedef {Object} Share
+ * @typedef {Object} ShareItem
  * @property {number} access_count
  * @property {number} created_at - timestamp
  * @property {String} created_by
@@ -48,8 +63,175 @@
  * @property {string} id
  * @property {string} item_id
  * @property {string} item_name
- * @property {string} item_type
+ * @property {ItemTypeEnum} item_type
  * @property {SharePermissions} permissions
  * @property {string | null} token
  * @property {string} url
  */
+
+/**
+ * @typedef {Object} CreateShare
+ * @property {string} item_id
+ * @property {string|null} [item_name]
+ * @property {ItemTypeEnum} item_type
+ * @property {string|null} password
+ * @property {number|null} expires_at - timestamp
+ * @property {SharePermissions|null} permissions
+ */
+
+/**
+ * @typedef {Object} UpdateShare
+ * @property {string|null} password
+ * @property {number|null} expires_at - timestamp
+ * @property {SharePermissions|null} permissions
+ */
+
+/**
+ * @typedef {Object} FavoriteItem
+ * @property {string} id
+ * @property {string} user_id
+ * @property {string} item_id /// ID of the favorited item (file or folder)
+ * @property {ItemTypeEnum} item_type
+ * @property {number} created_at
+ * @property {string|null} item_name: null if folder
+ * @property {number|null} item_size null if folder
+ * @property {string|null} item_mime_type if file
+ * @property {string|null} parent_id
+ * @property {number|null} modified_at: Option<DateTime<Utc>>,
+ * @property {String} item_path Full human-readable path (e.g. "Documents/Work" for a folder, "Documents/Work/report.pdf" for a file)
+ * @property {String} icon_class
+ * @property {String} icon_special_class
+ * @property {String} category
+ * @property {String} size_formatted
+ */
+
+/**
+ * @typedef {Object} TrashItem
+ * @property {string} id
+ * @property {string} original_id
+ * @property {ItemTypeEnum} item_type
+ * @property {string} name
+ * @property {string} original_path - timestamp
+ * @property {number} trashed_at
+ * @property {number} days_until_deletion
+ * @property {string} category
+ * @property {string} icon_class
+ * @property {string} icon_special_class
+ */
+
+/**
+ * @typedef {Object} User
+ * @property {string} id
+ * @property {string} username
+ * @property {string} email
+ * @property {string} role
+ * @property {number} storage_quota_bytes
+ * @property {number} storage_used_bytes
+ * @property {number} created_at
+ * @property {number} updated_at
+ * @property {number} last_login_at
+ * @property {boolean} active
+ * @property {string}  auth_provider
+ */
+
+/**
+ * @typedef {Object} AuthResponse
+ * @property {User} user
+ * @property {String} access_token
+ * @property {String} refresh_token
+ * @property {String} token_type
+ * @property {number} expires_in
+ */
+
+/**
+ * @typedef {'user' | 'admin'} RoleEnum
+ */
+
+/**
+ * @typedef {"relevance" | "name" | "name_desc" | "date" | "date_desc" | "size" | "size_desc"} SortByEnnum
+ */
+
+/**
+ * @typedef {Object} SearchCriteria
+ * @property {SortByEnnum} sort_by
+ * @property {boolean} recursive
+ * @property {number} limit
+ * @property {number} offset
+ *
+ * @property {String} [name_contains]
+ * @property {String[]} [file_types] pdf, jpg, ...
+ * @property {String} [folder_id]
+ *
+ *
+ * @property {number} [min_size]
+ * @property {number} [max_size]
+ *
+ * @property {number} [created_before]
+ * @property {number} [created_after]
+ *
+ * @property {number} [modified_before]
+ * @property {number} [modified_after]
+ */
+
+/**
+ * @typedef {Object} SearchResults
+ * FIXME: is in fact Vec<SearchFileResultDto>,
+ * @property {FileItem[]} files
+ * FIXME: is infact Vec<SearchFolderResultDto>,
+ * @property {FolderItem[]} folders:
+ * @property {number | null} total_count
+ * @property {number} limit
+ * @property {number} offset
+ * @property {boolean} has_more
+ * @property {number} query_time_ms
+ * @property {string} sort_by
+ */
+
+/**
+ * @typedef {Object} Playlist
+ * @property {String} id
+ * @property {String} name
+ * @property {String | null} description
+ * @property {String} owner_id
+ * @property {boolean} is_public
+ * @property {String | null} cover_file_id
+ * @property {number} track_count
+ * @property {number} total_duration_secs
+ * @property {number} created_at
+ * @property {number} updated_at
+ */
+
+/**
+ * @typedef {Object} PlaylistItem
+ * @property {String} id
+ * @property {String} playlist_id
+ * @property {String} file_id
+ * @property {number} position
+ * @property {number} added_at
+ * @property {String|null} file_name
+ * @property {number|null} file_size
+ * @property {String|null} mime_type
+ * @property {String|null} title
+ * @property {String|null} artist
+ * @property {String|null} album
+ * @property {number|null} duration_secs
+ */
+
+/**
+ * @typedef {Object} Musicshare
+ * @property {String} user_id
+ * @property {boolean|null} can_write
+ */
+
+/**
+ * @typedef {Object} FileMetadata
+ * @property {String} file_id
+ * @property {number} captured_at
+ * @property {number|null} latitude
+ * @property {number|null} longitude
+ * @property {String|null} camera_make
+ * @property {String|null} camera_model
+ * @property {number|null} orientation
+ * @property {number|null} width
+ * @property {number|null} height
+ */
diff --git a/static/js/features/auth/auth.js b/static/js/features/auth/auth.js
index 61aa0d7a..f467f364 100644
--- a/static/js/features/auth/auth.js
+++ b/static/js/features/auth/auth.js
@@ -6,6 +6,10 @@
 import { getCsrfHeaders } from '../../core/csrf.js';
 import { i18n } from '../../core/i18n.js';
 
+/**
+ * @import {AuthResponse, RoleEnum, User} from '../../core/types.js'
+ */
+
 // API endpoints
 const API_URL = '/api/auth';
 const LOGIN_ENDPOINT = `${API_URL}/login`;
@@ -41,6 +45,18 @@ function inputVal(id) {
 }
 
 // Language selector texts (used before i18n is loaded)
+/**
+ * @typedef {Object} PreTranslatedText
+ * @property {string} title
+ * @property {string} subtitle
+ * @property {string} continue
+ * @property {string} autodetected
+ * @property {string} moreLanguages
+ * @property {string} modalTitle
+ * @property {string} searchPlaceholder
+ */
+
+/** @type {Record<String,PreTranslatedText>} */
 const LANGUAGE_TEXTS = {
     en: {
         title: 'Welcome!',
@@ -145,6 +161,16 @@ const LANGUAGE_TEXTS = {
 
 // Complete language registry — add new languages here, they'll appear automatically
 // `popular: true` languages show as cards on the main screen, the rest in the modal
+/**
+ * @typedef {Object} Lang
+ * @property {string} code
+ * @property {string} name
+ * @property {string} nativeName
+ * @property {string} flag
+ * @property {boolean} popular
+ */
+
+/** @type {Lang[]} */
 export const ALL_LANGUAGES = [
     {
         code: 'en',
@@ -377,9 +403,18 @@ export const ALL_LANGUAGES = [
 // --- Panel visibility helpers ---
 // The `.hidden` CSS class uses `display: none !important`, so inline
 // `style.display` can never override it.  Always toggle the class instead.
+/**
+ *
+ * @param {HTMLElement} el
+ */
 function showPanel(el) {
     if (el) el.classList.remove('hidden');
 }
+
+/**
+ *
+ * @param {HTMLElement} el
+ */
 function hidePanel(el) {
     if (el) el.classList.add('hidden');
 }
@@ -434,13 +469,18 @@ function detectBrowserLanguage() {
     return ALL_LANGUAGES[0]; // fallback to English
 }
 
-// Build a language option element (card style)
+/**
+ * Build a language option element (card style)
+ * @param {Lang} lang
+ * @param {boolean} isSelected
+ * @returns
+ */
 function buildLanguageCard(lang, isSelected) {
     const item = document.createElement('div');
     item.className = `lang-picker-item${isSelected ? ' selected' : ''}`;
     item.setAttribute('data-lang', lang.code);
     item.setAttribute('role', 'option');
-    item.setAttribute('aria-selected', isSelected);
+    item.setAttribute('aria-selected', String(isSelected));
     item.innerHTML = `
         <span class="lang-picker-item-flag">${lang.flag}</span>
         <span class="lang-picker-item-name">${lang.nativeName}</span>
@@ -596,7 +636,10 @@ function initLanguageSelector() {
     });
 }
 
-// Update language panel texts based on selected language
+/**
+ * Update language panel texts based on selected language
+ * @param {string} lang
+ */
 function updateLanguagePanelTexts(lang) {
     const texts = LANGUAGE_TEXTS[lang] || LANGUAGE_TEXTS.en;
     const titleEl = document.getElementById('language-title');
@@ -1089,6 +1132,9 @@ if (isLoginPage && adminSetupForm) {
 
 /**
  * Login with username and password
+ * @param {string} username
+ * @param {string} password
+ * @returns {Promise<AuthResponse>}
  */
 async function login(username, password) {
     try {
@@ -1126,8 +1172,9 @@ async function login(username, password) {
 
         // Parse the JSON response
         try {
+            /** @type {AuthResponse} */
             const data = await response.json();
-            console.log('Login successful, received data');
+            console.log(`Login successful for user id ${data.user.id}, received data`);
             return data;
         } catch (jsonError) {
             console.error('Error parsing login response:', jsonError);
@@ -1141,6 +1188,11 @@ async function login(username, password) {
 
 /**
  * Register a new user
+ * @param {string} username
+ * @param {string} email
+ * @param {string} password
+ * @param {RoleEnum} [role]
+ * @returns {Promise<User>}
  */
 async function register(username, email, password, role = 'user') {
     try {
@@ -1170,8 +1222,9 @@ async function register(username, email, password, role = 'user') {
 
         // Parse the JSON response
         try {
+            /** @type {User} */
             const data = await response.json();
-            console.log('Registration successful, received data');
+            console.log(`Registration successful, user created: ${data.id}, received data`);
             return data;
         } catch (jsonError) {
             console.error('Error parsing registration response:', jsonError);
diff --git a/static/js/features/files/contextMenus.js b/static/js/features/files/contextMenus.js
index 0f02569f..12fd5e09 100644
--- a/static/js/features/files/contextMenus.js
+++ b/static/js/features/files/contextMenus.js
@@ -20,10 +20,19 @@ import { inlineViewer } from './inlineViewer.js';
 import { multiSelect } from './multiSelect.js';
 import { wopiEditor } from './wopiEditor.js';
 
+/**
+ *  @import {FolderItem, FileItem, ItemTypeEnum, Playlist} from '../../core/types.js'
+ */
+
+/** @type {EventListener | null} */
 let _moveDialogEscapeHandler = null;
 
 // Context Menus Module
 const contextMenus = {
+    /**
+     * @param {string} optionId
+     * @param {boolean} isFavorite
+     */
     _setFavoriteOptionLabel(optionId, isFavorite) {
         const option = document.getElementById(optionId);
         if (!option) return;
@@ -308,11 +317,13 @@ const contextMenus = {
         // Note: We don't use stopPropagation because all Escape handlers are on document level
         // Each handler checks its own state, so multiple dialogs can be closed with multiple Escape presses
         if (!_moveDialogEscapeHandler) {
-            _moveDialogEscapeHandler = (e) => {
-                if (e.key === 'Escape' && !moveFileDialog?.classList.contains('hidden')) {
-                    this.closeMoveDialog();
+            _moveDialogEscapeHandler = /** @type {EventListener} */ (
+                (/** @type {KeyboardEvent} */ e) => {
+                    if (e.key === 'Escape' && !moveFileDialog?.classList.contains('hidden')) {
+                        this.closeMoveDialog();
+                    }
                 }
-            };
+            );
             document.addEventListener('keydown', _moveDialogEscapeHandler);
         }
 
@@ -385,8 +396,8 @@ const contextMenus = {
 
     /**
      * Show move dialog for a file or folder
-     * @param {Object} item - File or folder object
-     * @param {string} mode - 'file' or 'folder'
+     * @param {FolderItem | FileItem} item - File or folder object
+     * @param {ItemTypeEnum} mode
      */
     async showMoveDialog(item, mode) {
         // Set mode
@@ -405,15 +416,15 @@ const contextMenus = {
         // Start at the parent of the item being moved (so user sees siblings and can navigate)
         let startFolderId = null;
         let startFolderName = null;
-        if (mode === 'file' && item.folder_id) {
-            startFolderId = item.folder_id;
+        if (mode === 'file' && /** @type {FileItem} */ (item).folder_id) {
+            startFolderId = /** @type {FileItem} */ (item).folder_id;
             // We need the folder name for breadcrumb - try to get it from current view
             const folderEl = document.querySelector(`[data-folder-id="${startFolderId}"]`);
             if (folderEl) {
                 startFolderName = folderEl.querySelector('.folder-name, .item-name')?.textContent || null;
             }
-        } else if (mode === 'folder' && item.parent_id) {
-            startFolderId = item.parent_id;
+        } else if (mode === 'folder' && /** @type {FolderItem} */ (item).parent_id) {
+            startFolderId = /** @type {FolderItem} */ (item).parent_id;
         } else {
             // If item is at root level, start at user's home folder
             startFolderId = app.userHomeFolderId || null;
@@ -492,6 +503,7 @@ const contextMenus = {
 
             // The contents endpoint returns an array of child folders
             // The fallback /api/folders returns root folders (home folder itself)
+            /** @type {FolderItem[]} */
             const folders = Array.isArray(data) ? data : data.folders || [];
             console.log('[Move Dialog] Loaded folders:', folders.length, 'folders:', folders);
 
@@ -623,6 +635,9 @@ const contextMenus = {
 
     /**
      * Render breadcrumb navigation for move dialog
+     * @param {HTMLElement | null} container
+     * @param {Array<{id: string, name: string}>} breadcrumb
+     * @param {string | null} _currentFolderId
      */
     _renderMoveDialogBreadcrumb(container, breadcrumb, _currentFolderId) {
         if (!container) return;
@@ -666,7 +681,7 @@ const contextMenus = {
         }
 
         // Breadcrumb path
-        breadcrumb.forEach((segment, index) => {
+        breadcrumb.forEach((/** @type {{id: string, name: string}} */ segment, /** @type {number} */ index) => {
             const separator = document.createElement('span');
             separator.className = 'move-breadcrumb-separator';
             separator.textContent = '>';
@@ -709,8 +724,8 @@ const contextMenus = {
 
     /**
      * Show share dialog for files or folders
-     * @param {Object} item - File or folder object
-     * @param {string} itemType - 'file' or 'folder'
+     * @param {FileItem | FolderItem} item - File or folder object
+     * @param {ItemTypeEnum} itemType
      */
     async showShareDialog(item, itemType) {
         try {
@@ -835,7 +850,7 @@ const contextMenus = {
                                 btn.closest('.existing-share-item').remove();
                                 if (existingSharesContainer.children.length === 0) {
                                     document.getElementById('existing-shares-section').classList.add('hidden');
-                                    ui.setSharedVisualState(item.id, item.type, false);
+                                    ui.setSharedVisualState(item.id, itemType, false);
                                 }
                             }
                         });
@@ -920,7 +935,7 @@ const contextMenus = {
             }
 
             // Update Item's shared badge
-            ui.setSharedVisualState(item.id, item.type, true);
+            ui.setSharedVisualState(item.id, itemType, true);
 
             // Show success message
             ui.showNotification(i18n.t('notifications.link_created'), i18n.t('notifications.share_success'));
@@ -994,8 +1009,14 @@ const contextMenus = {
         app.notificationShareUrl = null;
     },
 
+    /** @type {String | null} */
     _selectedPlaylistId: null,
 
+    /**
+     *
+     * @param {FileItem} file
+     * @returns
+     */
     async showPlaylistDialog(file) {
         const dialog = document.getElementById('playlist-dialog');
         const container = document.getElementById('playlist-select-container');
@@ -1031,6 +1052,7 @@ const contextMenus = {
             const resp = await fetch('/api/playlists', { credentials: 'include' });
             if (!resp.ok) throw new Error('Failed to load playlists');
 
+            /** @type {Playlist[]} */
             const playlists = await resp.json();
             this._renderPlaylistSelect(container, playlists);
         } catch (err) {
@@ -1039,6 +1061,12 @@ const contextMenus = {
         }
     },
 
+    /**
+     *
+     * @param {HTMLElement} container
+     * @param {Playlist[]} playlists
+     * @returns
+     */
     _renderPlaylistSelect(container, playlists) {
         container.innerHTML = '';
 
@@ -1124,6 +1152,12 @@ const contextMenus = {
         this._selectedPlaylistId = null;
     },
 
+    /**
+     *
+     * @param {string} str
+     * @returns
+     */
+    //FIXME: move to common library
     _escapeHtml(str) {
         if (!str) return '';
         return str.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;');
diff --git a/static/js/features/files/fileOperations.js b/static/js/features/files/fileOperations.js
index 348936b4..be9924ca 100644
--- a/static/js/features/files/fileOperations.js
+++ b/static/js/features/files/fileOperations.js
@@ -11,10 +11,18 @@ import { getCsrfHeaders, getCsrfToken } from '../../core/csrf.js';
 import { i18n } from '../../core/i18n.js';
 import { notifications } from '../../core/notifications.js';
 
+/** @import {TrashItem} from '../../core/types.js' */
+
+/**
+ * @typedef {Object} BatchResult
+ * @property {number} success number of files|folders sucessfully updated
+ * @property {number} errors  number of files|folders in error
+ * /
+
 /**
  * Get authorization headers for API requests.
  * Tokens are now in HttpOnly cookies — no explicit Authorization header needed.
- * @returns {Object} Headers object
+ * @returns {Record<String, String>} Headers object
  */
 function getAuthHeaders() {
     return { ...getCsrfHeaders() };
@@ -25,15 +33,26 @@ const fileOps = {
     // ========================================================================
     // Upload progress — notification bell integration
     // ========================================================================
+    /** @type {string | null} */
     _currentBatchId: null,
+
+    /** @type {boolean} */
     _isUploading: false, // Guard against concurrent upload calls
 
-    /** Start a new upload batch in the notification bell */
+    /**
+     * Start a new upload batch in the notification bell
+     * @param {number} totalFiles
+     * @param {string} [folderName]
+     */
     _initUploadToast(totalFiles, folderName) {
         this._currentBatchId = notifications.addUploadBatch(totalFiles, folderName);
     },
 
-    /** Finalise the batch in the notification bell */
+    /**
+     * Finalise the batch in the notification bell
+     * @param {number} successCount
+     * @param {number} totalFiles
+     * */
     _finishUploadToast(successCount, totalFiles) {
         if (this._currentBatchId) {
             notifications.finishBatch(this._currentBatchId, successCount, totalFiles);
@@ -44,6 +63,8 @@ const fileOps = {
      * Some drag-and-drop sources can inject directory placeholders into
      * DataTransfer.files. Browsers fail those with net::ERR_ACCESS_DENIED
      * when trying to send them as normal files.
+     * @param {File} file
+     * @returns {Promise<boolean>}
      */
     _canReadFileBlob(file) {
         return new Promise((resolve) => {
@@ -58,10 +79,24 @@ const fileOps = {
         });
     },
 
+    // FIXME: prefer exceptions for errors
+    /**
+     * @typedef {Object} UploadAnswer
+     * @property {boolean} ok
+     * @property {any} [data]
+     * @property {string} [errorMsg]
+     * @property {boolean} [isQuotaError]
+     * @property {boolean} [isTimeout]
+     */
+
     /**
      * Upload a single file via XMLHttpRequest with progress events.
      * Progress is reported to the notification bell via batchId + fileName.
      * Returns a promise that resolves with { ok, data?, errorMsg?, isQuotaError? }.
+     * @param {FormData} formData
+     * @param {string} batchId
+     * @param {string} fileName
+     * @param {number} [timeoutMs=120000]
      */
     _uploadFileXHR(formData, batchId, fileName, timeoutMs = 120000) {
         return new Promise((resolve) => {
@@ -76,9 +111,16 @@ const fileOps = {
             let lastProgressPctSent = -1;
 
             let isSettled = false;
+            /** @type {ReturnType<typeof setTimeout>} */
             let stallTimer = null;
+            /** @type {ReturnType<typeof setTimeout>} */
             let hardTimer = null;
 
+            /**
+             *
+             * @param {number} pct
+             * @param {'uploading' | 'done' | 'error'} status
+             */
             const safeUpdateFile = (pct, status) => {
                 if (!notif || !batchId) return;
                 try {
@@ -88,6 +130,11 @@ const fileOps = {
                 }
             };
 
+            /**
+             *
+             * @param {UploadAnswer} result
+             * @returns
+             */
             const finalize = (result) => {
                 if (isSettled) return;
                 isSettled = true;
@@ -219,6 +266,12 @@ const fileOps = {
      * Used by folder uploads to avoid browser XHR edge-cases with dragged entries.
      * Returns { ok, data?, errorMsg?, isQuotaError?, isTimeout? }.
      */
+    /**
+     *
+     * @param {*} formData
+     * @param {*} timeoutMs
+     * @returns {Promise<UploadAnswer>}
+     */
     async _uploadFileFetch(formData, timeoutMs = 60000) {
         const controller = new AbortController();
         const timeoutId = setTimeout(() => controller.abort(), timeoutMs);
@@ -254,11 +307,13 @@ const fileOps = {
             const isQuotaError = (body && typeof body === 'object' && body.error_type === 'QuotaExceeded') || response.status === 507;
             return { ok: false, errorMsg, isQuotaError };
         } catch (e) {
-            const isTimeout = e?.name === 'AbortError';
+            const isTimeout = /** @type {Error} */ (e)?.name === 'AbortError';
             return {
                 ok: false,
                 isTimeout,
-                errorMsg: isTimeout ? `Timeout after ${Math.round(timeoutMs / 1000)}s` : `Fetch upload failed: ${e?.message || 'network error'}`
+                errorMsg: isTimeout
+                    ? `Timeout after ${Math.round(timeoutMs / 1000)}s`
+                    : `Fetch upload failed: ${/** @type {Error} */ (e)?.message || 'network error'}`
             };
         } finally {
             clearTimeout(timeoutId);
@@ -458,6 +513,7 @@ const fileOps = {
 
         try {
             // Filter unreadable entries
+            /** @type {Array<{file: File, relativePath: string}>} */
             const validEntries = [];
             for (const e of rawEntries) {
                 // eslint-disable-next-line no-await-in-loop
@@ -560,12 +616,18 @@ const fileOps = {
             const TIMEOUT_MIN_MS = 10000; // floor for tiny files
             const TIMEOUT_MS_ZERO = 3000; // 3s for 0-byte files
 
+            /**
+             *
+             * @param {number} idx
+             * @returns
+             */
             const uploadOneFile = async (idx) => {
                 if (quotaStop) return;
                 const entry = validEntries[idx];
                 const file = entry.file;
                 const rel = entry.relativePath || file.name;
 
+                /** @type {UploadAnswer} */
                 let result = { ok: false, errorMsg: 'Unknown client error' };
                 try {
                     const parts = rel.split('/');
@@ -577,6 +639,7 @@ const fileOps = {
                     // but block on open(). Pre-read only 0-byte files into
                     // memory; files with size>0 are always regular files and
                     // go straight to FormData (zero extra memory copy).
+                    /** @type {Blob} */
                     let uploadFile = file; // default: use original File
                     if (file.size === 0) {
                         try {
@@ -616,7 +679,7 @@ const fileOps = {
                 } catch (e) {
                     result = {
                         ok: false,
-                        errorMsg: `Client exception: ${e?.message || 'unknown'}`
+                        errorMsg: `Client exception: ${/** @type {Error} */ (e)?.message || 'unknown'}`
                     };
                     console.error(`[UPLOAD EXCEPTION] #${idx} ${rel}:`, e);
                 }
@@ -823,12 +886,6 @@ const fileOps = {
         }
     },
 
-    /**
-    * @typedef {Object} BatchResult
-    * @property {number} success number of files|folders sucessfully updated
-    * @property {number} errors  number of files|folders in error
-    * /
-
     /**
      * Move files & folders
      * @param {string[]} fileIds - File IDs
@@ -941,18 +998,12 @@ const fileOps = {
         return res.ok;
     },
 
-    /**
-     * @typedef {Object} BatchCopyReturn
-     * @property {number} success
-     * @property {number} errors
-     */
-
     /**
      * Copy files & folders
      * @param {string[]} fileIds - File IDs
      * @param {string[]} folderIds - Folder IDs
      * @param {string} targetFolderId - Target folder ID
-     * @returns {Promise<BatchCopyReturn>} - Success status
+     * @returns {Promise<BatchResult>} - Success status
      */
     async batchCopy(fileIds, folderIds, targetFolderId) {
         // FIXME ensure not moving a folder into itself
@@ -1010,7 +1061,6 @@ const fileOps = {
      * Rename a file
      * @param {string} fileId - File ID
      * @param {string} newName - New file name
-     * @returns {Promise<string|null>} - null on success, error message string on failure
      */
     async renameFile(fileId, newName) {
         try {
@@ -1052,13 +1102,6 @@ const fileOps = {
      * Rename a folder
      * @param {string} folderId - Folder ID
      * @param {string} newName - New folder name
-     * @returns {Promise<boolean>} - Success status
-     */
-    /**
-     * Rename a folder
-     * @param {string} folderId - Folder ID
-     * @param {string} newName - New folder name
-     * @returns {Promise<string|null>} - null on success, error message string on failure
      */
     async renameFolder(folderId, newName) {
         try {
@@ -1170,7 +1213,7 @@ const fileOps = {
                 // If we're inside the folder we just deleted, go back up
                 if (app.currentPath === folderId) {
                     app.currentPath = '';
-                    ui.updateBreadcrumb('');
+                    ui.updateBreadcrumb();
                 }
                 loadFiles();
                 ui.showNotification('Folder moved to trash', `"${folderName}" moved to trash`);
@@ -1186,7 +1229,7 @@ const fileOps = {
                     // If we're inside the folder we just deleted, go back up
                     if (app.currentPath === folderId) {
                         app.currentPath = '';
-                        ui.updateBreadcrumb('');
+                        ui.updateBreadcrumb();
                     }
                     loadFiles();
                     ui.showNotification('Folder deleted', `"${folderName}" deleted successfully`);
@@ -1205,7 +1248,7 @@ const fileOps = {
 
     /**
      * Get trash items
-     * @returns {Promise<Array>} - List of trash items
+     * @returns {Promise<Array<TrashItem>>} - List of trash items
      */
     async getTrashItems() {
         try {
@@ -1214,7 +1257,7 @@ const fileOps = {
             });
 
             if (response.ok) {
-                return await response.json();
+                return /** @type {TrashItem[]} */ (await response.json());
             } else {
                 console.error('Error fetching trash items:', response.statusText);
                 return [];
diff --git a/static/js/features/files/inlineViewer.js b/static/js/features/files/inlineViewer.js
index 1f44e9fe..c4b14c74 100644
--- a/static/js/features/files/inlineViewer.js
+++ b/static/js/features/files/inlineViewer.js
@@ -8,6 +8,8 @@ import { app } from '../../app/state.js';
 import { isTextViewable } from '../../core/formatters.js';
 import { wopiEditor } from './wopiEditor.js';
 
+/** @import {FileItem} from '../../core/types.js' */
+
 class InlineViewer {
     constructor() {
         this.setupViewer();
@@ -93,6 +95,11 @@ class InlineViewer {
         console.log('Inline viewer initialized');
     }
 
+    /**
+     *
+     * @param {FileItem} file
+     * @returns
+     */
     async openFile(file) {
         console.log('Opening file:', file);
 
@@ -115,7 +122,7 @@ class InlineViewer {
 
         // Get container
         const modal = document.getElementById('inline-viewer-modal');
-        const container = modal.querySelector('.inline-viewer-container');
+        const container = /** @type {HTMLDivElement} */ (modal.querySelector('.inline-viewer-container'));
         const title = modal.querySelector('.inline-viewer-title');
 
         // Clear container
@@ -125,12 +132,12 @@ class InlineViewer {
         title.textContent = file.name;
 
         // Set controls visibility
-        const controls = modal.querySelector('.inline-viewer-controls');
+        const controls = /** @type {HTMLDivElement} */ (modal.querySelector('.inline-viewer-controls'));
 
         // Show viewer based on file type
         if (isImage) {
             // Show zoom controls
-            controls.style.display = 'flex';
+            controls.classList.remove('hidden');
 
             // Show loading indicator
             const loader = document.createElement('div');
@@ -142,7 +149,7 @@ class InlineViewer {
             this.createBlobUrlViewer(file, 'image', container, loader);
         } else if (file.mime_type && file.mime_type === 'application/pdf') {
             // Hide zoom controls for PDFs
-            controls.style.display = 'none';
+            controls.classList.add('hidden');
 
             // Show loading indicator
             const loader = document.createElement('div');
@@ -152,9 +159,9 @@ class InlineViewer {
 
             // Create PDF viewer using object tag with blob URL
             this.createBlobUrlViewer(file, 'pdf', container, loader);
-        } else if (file.mime_type && this.isTextViewable(file.mime_type)) {
+        } else if (file.mime_type && isTextViewable(file.mime_type)) {
             // Hide zoom controls for text files
-            controls.style.display = 'none';
+            controls.classList.add('hidden');
 
             // Show loading indicator
             const loader = document.createElement('div');
@@ -166,7 +173,7 @@ class InlineViewer {
             this.createTextViewer(file, container, loader);
         } else if (file.mime_type?.startsWith('audio/')) {
             // Hide zoom controls for audio
-            controls.style.display = 'none';
+            controls.classList.add('hidden');
 
             // Show loading indicator
             const loader = document.createElement('div');
@@ -178,7 +185,7 @@ class InlineViewer {
             this.createMediaViewer(file, 'audio', container, loader);
         } else if (file.mime_type?.startsWith('video/')) {
             // Hide zoom controls for video
-            controls.style.display = 'none';
+            controls.classList.add('hidden');
 
             // Show loading indicator
             const loader = document.createElement('div');
@@ -190,7 +197,7 @@ class InlineViewer {
             this.createMediaViewer(file, 'video', container, loader);
         } else {
             // Hide zoom controls for unsupported files
-            controls.style.display = 'none';
+            controls.classList.add('hidden');
 
             // Show unsupported file message
             const message = document.createElement('div');
@@ -209,12 +216,13 @@ class InlineViewer {
         modal.classList.add('active');
     }
 
-    // Check if a MIME type is text-viewable
-    isTextViewable(mimeType) {
-        return isTextViewable(mimeType);
-    }
-
     // Creates a text viewer using authenticated fetch
+    /**
+     *
+     * @param {FileItem} file
+     * @param {HTMLDivElement} container
+     * @param {*} loader
+     */
     async createTextViewer(file, container, loader) {
         try {
             console.log('Creating text viewer for:', file.name);
@@ -253,14 +261,20 @@ class InlineViewer {
         }
     }
 
-    // Creates a viewer using a Blob URL to avoid content-disposition header
-    async createBlobUrlViewer(file, type, container, loader) {
+    /**
+     * Creates a viewer using a Blob URL to avoid content-disposition header
+     * @param {FileItem} file
+     * @param {string} mediaType
+     * @param {HTMLDivElement} container
+     * @param {HTMLDivElement} loader
+     */
+    async createBlobUrlViewer(file, mediaType, container, loader) {
         try {
-            console.log('Creating blob URL viewer for:', file.name, 'type:', type);
+            console.log('Creating blob URL viewer for:', file.name, 'type:', mediaType);
 
             // Update loader to show progress bar for large files
-            let progressBar = null;
-            let progressText = null;
+            let progressBar = /** @type {HTMLElement|null} */ (null);
+            let progressText = /** @type {HTMLElement|null} */ (null);
             if (loader && file.size > 10 * 1024 * 1024) {
                 // Show progress for files > 10MB
                 loader.innerHTML = `
@@ -272,8 +286,8 @@ class InlineViewer {
             <div class="inline-viewer-progress-text">0%</div>
           </div>
         `;
-                progressBar = loader.querySelector('.inline-viewer-progress-fill');
-                progressText = loader.querySelector('.inline-viewer-progress-text');
+                progressBar = /** @type {HTMLElement|null} */ (loader.querySelector('.inline-viewer-progress-fill'));
+                progressText = /** @type {HTMLElement|null} */ (loader.querySelector('.inline-viewer-progress-text'));
             }
 
             // Use XMLHttpRequest instead of fetch to get better control over the response
@@ -322,7 +336,7 @@ class InlineViewer {
                 loader.parentNode.removeChild(loader);
             }
 
-            if (type === 'image') {
+            if (mediaType === 'image') {
                 console.log('Creating image viewer');
                 // Create image element
                 const img = document.createElement('img');
@@ -332,10 +346,10 @@ class InlineViewer {
                 container.appendChild(img);
 
                 // Add loading indicator until image loads
-                img.style.opacity = 0;
+                img.style.opacity = String(0);
                 img.onload = () => {
                     console.log('Image loaded successfully');
-                    img.style.opacity = 1;
+                    img.style.opacity = String(1);
                 };
 
                 img.onerror = () => {
@@ -343,7 +357,7 @@ class InlineViewer {
                     container.removeChild(img);
                     this.showErrorMessage(container);
                 };
-            } else if (type === 'pdf') {
+            } else if (mediaType === 'pdf') {
                 console.log('Creating PDF viewer');
 
                 // Create iframe for PDF (more reliable than object tag)
@@ -382,7 +396,13 @@ class InlineViewer {
         }
     }
 
-    // Creates an audio or video player using blob URL (authenticated fetch)
+    /**
+     * Creates an audio or video player using blob URL (authenticated fetch)
+     * @param {FileItem} file
+     * @param {string} mediaType
+     * @param {HTMLDivElement} container
+     * @param {HTMLDivElement} loader
+     */
     async createMediaViewer(file, mediaType, container, loader) {
         try {
             console.log(`Creating ${mediaType} player for:`, file.name);
@@ -485,7 +505,10 @@ class InlineViewer {
         }
     }
 
-    // Helper to show error message
+    /**
+     * Helper to show error message
+     * @param {HTMLDivElement} container
+     */
     showErrorMessage(container) {
         // Show error message
         const message = document.createElement('div');
@@ -505,7 +528,7 @@ class InlineViewer {
         const modal = document.getElementById('inline-viewer-modal');
 
         // stops audio/video before closing viewver
-        const media = modal.querySelector('audio, video');
+        const media = /** @type {HTMLMediaElement} */ (modal.querySelector('audio, video'));
         if (media && !media.paused) media.pause();
 
         // Hide modal
@@ -525,6 +548,10 @@ class InlineViewer {
         this.currentFile = null;
     }
 
+    /**
+     *
+     * @param {FileItem} file
+     */
     downloadFile(file) {
         fetch(`/api/files/${file.id}`, { credentials: 'same-origin' })
             .then((res) => {
@@ -544,9 +571,14 @@ class InlineViewer {
             .catch((err) => console.error('Download error:', err));
     }
 
+    /**
+     *
+     * @param {number} factor
+     * @returns
+     */
     zoomImage(factor) {
         const container = document.querySelector('.inline-viewer-container');
-        const img = container.querySelector('.inline-viewer-image');
+        const img = /** @type {HTMLDivElement} */ (container.querySelector('.inline-viewer-image'));
 
         if (!img) return;
 
@@ -560,7 +592,7 @@ class InlineViewer {
         scale = Math.max(0.1, Math.min(5.0, scale));
 
         // Save scale
-        img.dataset.scale = scale;
+        img.dataset.scale = String(scale);
 
         // Apply scale
         img.style.transform = `scale(${scale})`;
@@ -568,12 +600,12 @@ class InlineViewer {
 
     resetZoom() {
         const container = document.querySelector('.inline-viewer-container');
-        const img = container.querySelector('.inline-viewer-image');
+        const img = /** @type {HTMLDivElement} */ (container.querySelector('.inline-viewer-image'));
 
         if (!img) return;
 
         // Reset scale
-        img.dataset.scale = 1.0;
+        img.dataset.scale = String(1);
         img.style.transform = 'scale(1.0)';
     }
 }
diff --git a/static/js/features/files/multiSelect.js b/static/js/features/files/multiSelect.js
index f77194cd..de9c9525 100644
--- a/static/js/features/files/multiSelect.js
+++ b/static/js/features/files/multiSelect.js
@@ -9,8 +9,6 @@
 // TODO: rename into selection-bar ?
 // TODO: merge with photo part
 
-// @ts-check
-
 import { loadFiles } from '../../app/filesView.js';
 import { app } from '../../app/state.js';
 import { showConfirmDialog, ui } from '../../app/ui.js';
@@ -19,8 +17,14 @@ import { favorites } from '../library/favorites.js';
 import { contextMenus } from './contextMenus.js';
 import { getAuthHeaders } from './fileOperations.js';
 
+/**
+ * @import {ItemTypeEnum, LightItem} from '../../core/types.js'
+ * @import {BatchResult} from './fileOperations.js'
+ */
+
 const multiSelect = {
-    /** Currently selected items: Map<id, { id, name, type, parentId }> */
+    /** @type {Map<String, LightItem>} items: Map<id, { id, name, type, parentId }> */
+
     _selected: new Map(),
 
     /** Last clicked index for Shift-range selection */
@@ -49,6 +53,12 @@ const multiSelect = {
 
     // ── Helpers for i18n ────────────────────────────────────
 
+    /**
+     *
+     * @param {string} key
+     * @param {any} vars
+     * @returns
+     */
     _t(key, vars) {
         const val = i18n.t(key, vars);
         return val !== key ? val : null;
@@ -56,6 +66,14 @@ const multiSelect = {
 
     // ── Selection state management ──────────────────────────
 
+    /**
+     *
+     * @param {string} id
+     * @param {string} name
+     * @param {ItemTypeEnum} type
+     * @param {string} parentId
+     * @returns
+     */
     toggle(id, name, type, parentId) {
         if (this._selected.has(id)) {
             this._selected.delete(id);
@@ -65,10 +83,22 @@ const multiSelect = {
         return true;
     },
 
+    /**
+     *
+     * @param {string} id
+     * @param {string} name
+     * @param {ItemTypeEnum} type
+     * @param {string} parentId
+     * @returns
+     */
     select(id, name, type, parentId) {
         this._selected.set(id, { id, name, type, parentId });
     },
 
+    /**
+     *
+     * @param {string} id
+     */
     deselect(id) {
         this._selected.delete(id);
     },
@@ -80,7 +110,7 @@ const multiSelect = {
             el.classList.remove('selected');
         });
         document.querySelectorAll('.item-checkbox').forEach((cb) => {
-            cb.checked = false;
+            /** @type {HTMLInputElement} */ (cb).checked = false;
         });
         this._syncUI();
     },
@@ -111,11 +141,13 @@ const multiSelect = {
      * @return {ItemSelection}
      */
     getSelection(targtFolderId) {
+        /** @type {Array<string>} */
         const fileIds = [];
+        /** @type {Array<string>} */
         const folderIds = [];
 
         // TODO optimize & check if _selected is a better use
-        document.querySelectorAll(`div.file-item.selected`).forEach((item) => {
+        /** @type {NodeListOf<HTMLDivElement>} */ (document.querySelectorAll(`div.file-item.selected`)).forEach((item) => {
             if (item.dataset.fileId) {
                 fileIds.push(item.dataset.fileId);
             } else {
@@ -152,6 +184,10 @@ const multiSelect = {
 
     // ── DOM helpers ─────────────────────────────────────────
 
+    /**
+     *
+     * @param {HTMLDivElement} el
+     */
     _selectElement(el) {
         const info = this._extractInfo(el);
         if (info) {
@@ -160,18 +196,32 @@ const multiSelect = {
         }
     },
 
+    /**
+     *
+     * @param {string} containerId
+     * @param {string} selector
+     * @returns {void}
+     */
     _selectAllInContainer(containerId, selector) {
-        const container = document.getElementById(containerId);
+        const container = /** @type {HTMLDivElement} */ (document.getElementById(containerId));
         if (!container) return;
-        container.querySelectorAll(selector).forEach((el) => {
+        /** @type {NodeListOf<HTMLDivElement>} */ (container.querySelectorAll(selector)).forEach((el) => {
             this._selectElement(el);
         });
     },
 
+    /**
+     *
+     * @returns {HTMLDivElement[]}
+     */
     _getAllVisibleItems() {
-        return [...document.querySelectorAll('.file-item')];
+        return /** @type {HTMLDivElement[]} */ ([...document.querySelectorAll('.file-item')]);
     },
 
+    /**
+     * @param {HTMLDivElement} el
+     * @returns {LightItem}
+     */
     _extractInfo(el) {
         if (el.dataset.folderId && el.dataset.folderName !== undefined) {
             return {
@@ -194,6 +244,10 @@ const multiSelect = {
 
     // ── Click handler (shared by grid + list) ───────────────
 
+    /**
+     * @param {HTMLDivElement} el
+     * @param {MouseEvent} event
+     */
     handleToggleItem(el, event) {
         const items = this._getAllVisibleItems();
         const index = items.indexOf(el);
@@ -210,7 +264,7 @@ const multiSelect = {
                     const sel = iInfo.type === 'folder' ? `[data-folder-id="${iInfo.id}"]` : `[data-file-id="${iInfo.id}"]`;
                     document.querySelectorAll(sel).forEach((e) => {
                         e.classList.add('selected');
-                        const checkbox = e.querySelector('input[type="checkbox"]');
+                        const checkbox = /** @type {HTMLInputElement} */ (e.querySelector('input[type="checkbox"]'));
                         if (checkbox) checkbox.checked = true;
                     });
                 }
@@ -218,7 +272,7 @@ const multiSelect = {
         } else {
             const nowSelected = this.toggle(info.id, info.name, info.type, info.parentId);
             el.classList.toggle('selected', nowSelected);
-            const checkbox = el.querySelector('input[type="checkbox"]');
+            const checkbox = /** @type {HTMLInputElement} */ (el.querySelector('input[type="checkbox"]'));
             if (checkbox) checkbox.checked = nowSelected;
         }
         this._lastClickedIndex = index;
@@ -271,13 +325,13 @@ const multiSelect = {
 
     _syncItemCheckboxes() {
         document.querySelectorAll('.file-item').forEach((el) => {
-            const cb = el.querySelector('.item-checkbox');
+            const cb = /** @type {HTMLInputElement} */ (el.querySelector('.item-checkbox'));
             if (cb) cb.checked = el.classList.contains('selected');
         });
     },
 
     _syncSelectAllCheckbox() {
-        const cb = document.getElementById('select-all-checkbox');
+        const cb = /** @type {HTMLInputElement} */ (document.getElementById('select-all-checkbox'));
         if (!cb) return;
         const all = this._getAllVisibleItems();
         if (all.length === 0) {
@@ -454,9 +508,10 @@ const multiSelect = {
 
         // Keyboard shortcuts
         document.addEventListener('keydown', (e) => {
-            if (e.target.closest('input, textarea, [contenteditable], .rename-dialog, .share-dialog, .confirm-dialog')) return;
+            const target = /** @type {Element} */ (e.target);
+            if (target.closest('input, textarea, [contenteditable], .rename-dialog, .share-dialog, .confirm-dialog')) return;
 
-            const selectAllCheckbox = document.getElementById('select-all-checkbox');
+            const selectAllCheckbox = /** @type {HTMLInputElement} */ (document.getElementById('select-all-checkbox'));
             // ctrl+a cmd+a
             if ((e.ctrlKey || e.metaKey) && e.key === 'a') {
                 if (selectAllCheckbox) selectAllCheckbox.checked = true;
diff --git a/static/js/features/files/search.js b/static/js/features/files/search.js
index 1f678c79..417b6bbd 100644
--- a/static/js/features/files/search.js
+++ b/static/js/features/files/search.js
@@ -12,6 +12,10 @@ import { app } from '../../app/state.js';
 import { ui } from '../../app/ui.js';
 import { getAuthHeaders } from './fileOperations.js';
 
+/**
+ * @import {SearchCriteria, SearchResults} from '../../core/types.js'}
+ */
+
 const search = {
     /**
      * Perform a search using query parameters.
@@ -19,25 +23,29 @@ const search = {
      * relevance_score, icon_class, category, size_formatted, etc.
      *
      * @param {string} query - Search query
-     * @param {Object} options - Additional search options
-     * @returns {Promise<Object>} - Enriched search results from backend
+     * @param {SearchCriteria} [options] - Additional search options
+     * @returns {Promise<SearchResults>} - Enriched search results from backend
      */
-    async searchFiles(query, options = {}) {
+    async searchFiles(query, options) {
         try {
             const params = new URLSearchParams();
             params.append('query', query);
 
             if (options.folder_id) params.append('folder_id', options.folder_id);
-            if (options.recursive !== undefined) params.append('recursive', options.recursive);
-            if (options.file_types) params.append('type', options.file_types);
-            if (options.min_size) params.append('min_size', options.min_size);
-            if (options.max_size) params.append('max_size', options.max_size);
-            if (options.created_after) params.append('created_after', options.created_after);
-            if (options.created_before) params.append('created_before', options.created_before);
-            if (options.modified_after) params.append('modified_after', options.modified_after);
-            if (options.modified_before) params.append('modified_before', options.modified_before);
-            if (options.limit) params.append('limit', options.limit);
-            if (options.offset) params.append('offset', options.offset);
+            if (options.recursive !== undefined) params.append('recursive', String(options.recursive));
+            if (options.file_types) {
+                options.file_types.forEach((file_type) => {
+                    params.append('type', file_type);
+                });
+            }
+            if (options.min_size) params.append('min_size', String(options.min_size));
+            if (options.max_size) params.append('max_size', String(options.max_size));
+            if (options.created_after) params.append('created_after', String(options.created_after));
+            if (options.created_before) params.append('created_before', String(options.created_before));
+            if (options.modified_after) params.append('modified_after', String(options.modified_after));
+            if (options.modified_before) params.append('modified_before', String(options.modified_before));
+            if (options.limit) params.append('limit', String(options.limit));
+            if (options.offset) params.append('offset', String(options.offset));
             if (options.sort_by) params.append('sort_by', options.sort_by);
 
             const url = `/api/search?${params.toString()}`;
@@ -46,6 +54,7 @@ const search = {
             const response = await fetch(url, { headers: getAuthHeaders() });
 
             if (response.ok) {
+                /** @type {SearchResults} */
                 return await response.json();
             } else {
                 let errorText = '';
@@ -66,7 +75,10 @@ const search = {
                 folders: [],
                 total_count: 0,
                 query_time_ms: 0,
-                sort_by: 'relevance'
+                sort_by: 'relevance',
+                limit: 0,
+                offset: 0,
+                has_more: false
             };
         }
     },
@@ -76,15 +88,15 @@ const search = {
      * Returns lightweight name suggestions without full search overhead.
      *
      * @param {string} query - Prefix to search for
-     * @param {Object} options - { folder_id, limit }
+     * @param {SearchCriteria} [options] - { folder_id, limit }
      * @returns {Promise<Object>} - { suggestions: [...], query_time_ms }
      */
-    async getSuggestions(query, options = {}) {
+    async getSuggestions(query, options) {
         try {
             const params = new URLSearchParams();
             params.append('query', query);
             if (options.folder_id) params.append('folder_id', options.folder_id);
-            if (options.limit) params.append('limit', options.limit);
+            if (options.limit) params.append('limit', String(options.limit));
 
             const url = `/api/search/suggest?${params.toString()}`;
             const response = await fetch(url, { headers: getAuthHeaders() });
@@ -111,7 +123,7 @@ const search = {
      * - query_time_ms: Server-side query execution time
      * - sort_by: Active sort order
      *
-     * @param {Object} results - Enriched search results from backend
+     * @param {SearchResults} results - Enriched search results from backend
      */
     displaySearchResults(results) {
         ui.resetFilesList(); // ensure also list visible & error hidden
diff --git a/static/js/features/files/wopiEditor.js b/static/js/features/files/wopiEditor.js
index 8401fe47..64f79445 100644
--- a/static/js/features/files/wopiEditor.js
+++ b/static/js/features/files/wopiEditor.js
@@ -19,6 +19,7 @@ class WopiEditor {
     /**
      * Check if a file can be opened in a WOPI editor by extension.
      * Fetches supported extensions from the server (cached after first call).
+     * @param {string} filename
      */
     async canEdit(filename) {
         const ext = filename.split('.').pop().toLowerCase();
@@ -28,6 +29,9 @@ class WopiEditor {
 
     /**
      * Open file in a modal overlay (default mode).
+     * @param {string} fileId
+     * @param {string} fileName
+     * @param {string} [action]
      */
     async openInModal(fileId, fileName, action) {
         action = action || 'edit';
@@ -38,6 +42,9 @@ class WopiEditor {
 
     /**
      * Open file in a new browser tab.
+     * @param {string} fileId
+     * @param {string} fileName
+     * @param {string} [action]
      */
     async openInTab(fileId, fileName, action) {
         action = action || 'edit';
@@ -53,6 +60,8 @@ class WopiEditor {
 
     /**
      * Fetch editor URL and WOPI token from the backend.
+     * @param {string} fileId
+     * @param {string} action
      */
     async _getEditorUrl(fileId, action) {
         const response = await fetch(`/api/wopi/editor-url?file_id=${encodeURIComponent(fileId)}&action=${encodeURIComponent(action)}`, {
@@ -68,6 +77,9 @@ class WopiEditor {
     /**
      * Some WOPI file types, such as PDFs, are view-only.
      * If an edit request returns 422, retry once in view mode.
+     * @param {string} fileId
+     * @param {string} fileName
+     * @param {string} action
      */
     async _getEditorUrlWithFallback(fileId, fileName, action) {
         try {
@@ -81,6 +93,11 @@ class WopiEditor {
         }
     }
 
+    /**
+     * @param {string} fileName
+     * @param {string} action
+     * @param {any} error
+     */
     _shouldRetryInViewMode(fileName, action, error) {
         if (action !== 'edit' || !error || !error.message) {
             return false;
@@ -92,6 +109,8 @@ class WopiEditor {
 
     /**
      * Show the editor in a full-screen modal with iframe.
+     * @param {Record<string, any>} editorData
+     * @param {string} fileName
      */
     _showModal(editorData, fileName) {
         this.closeEditor();
@@ -160,13 +179,13 @@ class WopiEditor {
         document.body.appendChild(modal);
 
         // ESC key handler
-        this._escHandler = function (e) {
+        this._escHandler = (/** @type {KeyboardEvent} */ e) => {
             if (e.key === 'Escape') this.closeEditor();
-        }.bind(this);
+        };
         document.addEventListener('keydown', this._escHandler);
 
         // Fix 7: Listen for postMessage from the editor iframe
-        this._messageHandler = function (e) {
+        this._messageHandler = (/** @type {MessageEvent} */ e) => {
             var data;
             try {
                 data = JSON.parse(e.data);
@@ -183,7 +202,7 @@ class WopiEditor {
                     if (sp) sp.remove();
                 }
             }
-        }.bind(this);
+        };
         window.addEventListener('message', this._messageHandler);
 
         form.submit();
diff --git a/static/js/features/library/favorites.js b/static/js/features/library/favorites.js
index b0031f7f..4e12c9a2 100644
--- a/static/js/features/library/favorites.js
+++ b/static/js/features/library/favorites.js
@@ -12,8 +12,10 @@ import { i18n } from '../../core/i18n.js';
 import { multiSelect } from '../files/multiSelect.js';
 import * as pathTooltip from '../pathTooltip.js';
 
+/** @import {FavoriteItem, FileItem, FolderItem} from '../../core/types.js' */
+
 const favorites = {
-    /** @type {Map<string, object>} key = "file:<id>" | "folder:<id>" */
+    /** @type {Map<string, FavoriteItem>} key = "file:<id>" | "folder:<id>" */
     _cache: new Map(),
 
     /** Whether the initial fetch from the server has completed */
@@ -25,6 +27,10 @@ const favorites = {
         return { ...getCsrfHeaders() };
     },
 
+    /**
+     * @param {string} id
+     * @param {string} type
+     */
     _cacheKey(id, type) {
         return `${type}:${id}`;
     },
@@ -33,6 +39,7 @@ const favorites = {
      * Replace the entire in-memory cache from an array of FavoriteItemDto
      * objects (as returned by the batch endpoint). Avoids an extra
      * GET /api/favorites round-trip.
+     * @param {any[]} items
      */
     _replaceCacheFromResponse(items) {
         this._cache.clear();
@@ -68,6 +75,7 @@ const favorites = {
                 return;
             }
 
+            /** @type {FavoriteItem[]} */
             const items = await response.json();
             this._cache.clear();
             for (const item of items) {
@@ -85,6 +93,8 @@ const favorites = {
 
     /**
      * Synchronous check used by ui.js to paint star icons.
+     * @param {string} id
+     * @param {string} type
      */
     isFavorite(id, type) {
         return this._cache.has(this._cacheKey(id, type));
@@ -92,6 +102,10 @@ const favorites = {
 
     /**
      * Add an item to favourites (server-first).
+     * @param {string} id
+     * @param {string} name
+     * @param {string} type
+     * @param {string} _parentId
      */
     async addToFavorites(id, name, type, _parentId) {
         try {
@@ -121,6 +135,8 @@ const favorites = {
 
     /**
      * Remove an item from favourites (server-first).
+     * @param {string} id
+     * @param {string} type
      */
     async removeFromFavorites(id, type) {
         try {
@@ -178,31 +194,51 @@ const favorites = {
                 return;
             }
 
+            /** @type {FolderItem[]} */
             const folders = [];
+
+            /** @type {FileItem[]} */
             const files = [];
+
             for (const item of this._cache.values()) {
+                // TODO: cast objects, but for that need to review user_id vs owner_id...
                 if (item.item_type === 'folder') {
-                    folders.push({
-                        id: item.item_id,
-                        name: item.item_name || item.item_id,
-                        parent_id: item.parent_id || '',
-                        modified_at: item.modified_at || item.created_at,
-                        path: item.item_path || ''
-                    });
+                    folders.push(
+                        // FIXME: better to grab the real values
+                        /** @type {FolderItem} */ {
+                            id: item.item_id,
+                            name: item.item_name || item.item_id,
+                            parent_id: item.parent_id || '',
+                            modified_at: item.modified_at || item.created_at,
+                            path: item.item_path || '',
+                            category: 'folder',
+                            created_at: item.created_at,
+                            icon_class: item.icon_class,
+                            icon_special_class: item.icon_special_class,
+                            owner_id: item.user_id,
+                            is_root: false
+                        }
+                    );
                 } else {
-                    files.push({
-                        id: item.item_id,
-                        name: item.item_name || item.item_id,
-                        folder_id: item.parent_id || '',
-                        mime_type: item.item_mime_type,
-                        icon_class: item.icon_class,
-                        icon_special_class: item.icon_special_class,
-                        category: item.category,
-                        size: item.item_size || 0,
-                        size_formatted: item.size_formatted,
-                        modified_at: item.modified_at || item.created_at,
-                        path: item.item_path || ''
-                    });
+                    files.push(
+                        // FIXME: better to grab the real values
+                        /** @type {FileItem} */ {
+                            id: item.item_id,
+                            name: item.item_name || item.item_id,
+                            folder_id: item.parent_id || '',
+                            mime_type: item.item_mime_type,
+                            icon_class: item.icon_class,
+                            icon_special_class: item.icon_special_class,
+                            category: item.category,
+                            size: item.item_size || 0,
+                            size_formatted: item.size_formatted,
+                            modified_at: item.modified_at || item.created_at,
+                            path: item.item_path || '',
+                            owner_id: item.user_id,
+                            created_at: item.created_at,
+                            sort_date: item.created_at
+                        }
+                    );
                 }
             }
             if (folders.length) ui.renderFolders(folders);
diff --git a/static/js/features/library/music.js b/static/js/features/library/music.js
index a75c8d00..efd2742f 100644
--- a/static/js/features/library/music.js
+++ b/static/js/features/library/music.js
@@ -6,17 +6,27 @@ import { oxiIcon } from '../../core/icons.js';
 import { Modal } from '../../core/modal.js';
 import { notifications } from '../../core/notifications.js';
 
+/** @import {FileItem, Musicshare, Playlist, PlaylistItem} from '../../core/types.js' */
+
 /**
  * OxiCloud - Music Library View
  * Playlist management with track listings and audio player
  */
 
 const musicView = {
+    /** @type {Playlist[]} */
     playlists: [],
+
+    /** @type {Playlist | null} */
     currentPlaylist: null,
+
+    /** @type {PlaylistItem[]} */
     currentTracks: [],
     loading: false,
+
+    /** @type {HTMLDivElement | null} */
     _container: null,
+
     _initialized: false,
     selected: new Set(),
 
@@ -72,11 +82,11 @@ const musicView = {
 
             if (!resp.ok) throw new Error('Failed to load playlists');
 
-            this.playlists = await resp.json();
+            this.playlists = /** @type {Playlist[]} */ (await resp.json());
             this._renderPlaylists();
         } catch (err) {
             console.error('Music load error:', err);
-            this._showError(err.message);
+            this._showError(/** @type {Error} */ (err).message);
         } finally {
             this.loading = false;
             this._showLoading(false);
@@ -209,7 +219,7 @@ const musicView = {
             )
             .join('');
 
-        listEl.querySelectorAll('.music-playlist-item').forEach((item) => {
+        /** @type {NodeListOf<HTMLDivElement>} */ (listEl.querySelectorAll('.music-playlist-item')).forEach((item) => {
             item.addEventListener('click', () => {
                 const id = item.dataset.id;
                 this._selectPlaylist(id);
@@ -269,6 +279,11 @@ const musicView = {
         }
     },
 
+    /**
+     *
+     * @param {string} playlistId
+     * @returns
+     */
     async _selectPlaylist(playlistId) {
         const playlist = this.playlists.find((p) => p.id === playlistId);
         if (!playlist) return;
@@ -308,13 +323,18 @@ const musicView = {
             togglePublicBtn.classList.toggle('active', playlist.is_public);
         }
 
-        document.querySelectorAll('.music-playlist-item').forEach((item) => {
+        /** @type {NodeListOf<HTMLDivElement>} */ (document.querySelectorAll('.music-playlist-item')).forEach((item) => {
             item.classList.toggle('active', item.dataset.id === playlistId);
         });
 
         await this._loadPlaylistTracks(playlistId);
     },
 
+    /**
+     *
+     * @param {string} playlistId
+     * @returns
+     */
     async _loadPlaylistTracks(playlistId) {
         const trackListEl = document.getElementById('music-track-list');
         if (!trackListEl) return;
@@ -333,7 +353,7 @@ const musicView = {
             this._renderTracks();
         } catch (err) {
             console.error('Track load error:', err);
-            trackListEl.innerHTML = `<div class="music-error">${err.message}</div>`;
+            trackListEl.innerHTML = `<div class="music-error">${/** @type {Error} */ (err).message}</div>`;
         }
     },
 
@@ -385,7 +405,7 @@ const musicView = {
                 )
                 .join('')}
         `;
-        trackListEl.querySelectorAll('.music-track').forEach((row) => {
+        /** @type {NodeListOf<HTMLDivElement>} */ (trackListEl.querySelectorAll('.music-track')).forEach((row) => {
             row.addEventListener('click', () => {
                 const idx = parseInt(row.dataset.idx, 10);
                 // Toggle selection
@@ -449,6 +469,11 @@ const musicView = {
         });
     },
 
+    /**
+     *
+     * @param {number} idx
+     * @returns
+     */
     _playTrack(idx) {
         if (!this.currentTracks[idx]) return;
 
@@ -487,8 +512,12 @@ const musicView = {
         this._createPlaylist(name.trim());
     },
 
+    /**
+     *
+     * @param {String} name
+     */
     async _createPlaylist(name) {
-        const createBtn = document.getElementById('music-create-playlist-btn');
+        const createBtn = /** @type {HTMLButtonElement} */ (document.getElementById('music-create-playlist-btn'));
         if (createBtn) createBtn.disabled = true;
         try {
             const resp = await fetch('/api/playlists', {
@@ -519,7 +548,7 @@ const musicView = {
                     icon: 'fa-exclamation-circle',
                     iconClass: 'error',
                     title: i18n.t('music.error'),
-                    text: err.message
+                    text: /** @type {Error} */ (err).message
                 });
             }
         } finally {
@@ -542,7 +571,7 @@ const musicView = {
         });
         if (!confirmed) return;
 
-        const deleteBtn = document.getElementById('music-delete-playlist-btn');
+        const deleteBtn = /** @type {HTMLButtonElement} */ (document.getElementById('music-delete-playlist-btn'));
         if (deleteBtn) deleteBtn.disabled = true;
         try {
             const resp = await fetch(`/api/playlists/${this.currentPlaylist.id}`, {
@@ -568,7 +597,7 @@ const musicView = {
                     icon: 'fa-exclamation-circle',
                     iconClass: 'error',
                     title: i18n.t('music.error'),
-                    text: err.message
+                    text: /** @type {Error} */ (err).message
                 });
             }
         } finally {
@@ -576,6 +605,11 @@ const musicView = {
         }
     },
 
+    /**
+     *
+     * @param {number|null} secs
+     * @returns
+     */
     _formatDuration(secs) {
         if (!secs) return '-';
         const mins = Math.floor(secs / 60);
@@ -583,11 +617,20 @@ const musicView = {
         return `${mins}:${s.toString().padStart(2, '0')}`;
     },
 
+    /**
+     *
+     * @param {string|null} str
+     * @returns
+     */
     _escapeHtml(str) {
         if (!str) return '';
         return str.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;');
     },
 
+    /**
+     *
+     * @param {boolean} show
+     */
     _showLoading(show) {
         const existing = this._container?.querySelector('.music-loading');
         if (show && !existing) {
@@ -600,6 +643,11 @@ const musicView = {
         }
     },
 
+    /**
+     *
+     * @param {string} message
+     * @returns
+     */
     _showError(message) {
         if (!this._container) return;
         this._container.innerHTML = `
@@ -647,7 +695,7 @@ const musicView = {
                     icon: 'fa-exclamation-circle',
                     iconClass: 'error',
                     title: i18n.t('music.error'),
-                    text: err.message
+                    text: /** @type {Error} */ (err).message
                 });
             }
         }
@@ -690,7 +738,7 @@ const musicView = {
                     icon: 'fa-exclamation-circle',
                     iconClass: 'error',
                     title: i18n.t('music.error'),
-                    text: err.message
+                    text: /** @type {Error} */ (err).message
                 });
             }
         }
@@ -731,8 +779,8 @@ const musicView = {
         requestAnimationFrame(() => overlay.classList.add('active'));
 
         const listEl = document.getElementById('music-picker-list');
-        const queryInput = document.getElementById('music-picker-query');
-        const addBtn = document.getElementById('music-picker-add-btn');
+        const queryInput = /** @type {HTMLInputElement} */ (document.getElementById('music-picker-query'));
+        const addBtn = /** @type {HTMLButtonElement} */ (document.getElementById('music-picker-add-btn'));
         const countEl = document.getElementById('music-picker-count');
         const selectedIds = new Set();
 
@@ -765,6 +813,11 @@ const musicView = {
             }
         };
 
+        /**
+         *
+         * @param {FileItem[]} files
+         * @returns
+         */
         const renderFiles = (files) => {
             if (files.length === 0) {
                 listEl.innerHTML = `<div class="music-picker-empty"><i class="fas fa-folder-open"></i> ${i18n.t('music.no_audio_files')}</div>`;
@@ -798,6 +851,7 @@ const musicView = {
         };
 
         // ── Debounced search ──
+        /** @type {ReturnType<typeof setTimeout> | null} */
         let searchTimer = null;
         queryInput.addEventListener('input', () => {
             clearTimeout(searchTimer);
@@ -857,6 +911,12 @@ const musicView = {
         fetchAudioFiles();
     },
 
+    /**
+     *
+     * @param {string} _trackId
+     * @param {string} fileId
+     * @returns
+     */
     async _removeTrackFromPlaylist(_trackId, fileId) {
         if (!this.currentPlaylist) return;
 
@@ -892,12 +952,18 @@ const musicView = {
                     icon: 'fa-exclamation-circle',
                     iconClass: 'error',
                     title: i18n.t('music.error'),
-                    text: err.message
+                    text: /** @type {Error} */ (err).message
                 });
             }
         }
     },
 
+    /**
+     *
+     * @param {number} fromIdx
+     * @param {number} toIdx
+     * @returns
+     */
     async _reorderTrack(fromIdx, toIdx) {
         if (!this.currentPlaylist) return;
 
@@ -923,7 +989,7 @@ const musicView = {
                     icon: 'fa-exclamation-circle',
                     iconClass: 'error',
                     title: i18n.t('music.error'),
-                    text: err.message
+                    text: /** @type {Error} */ (err).message
                 });
             }
             await this._loadPlaylistTracks(this.currentPlaylist.id);
@@ -967,8 +1033,8 @@ const musicView = {
         });
 
         dialog.querySelector('#music-share-add-btn').addEventListener('click', async () => {
-            const userInput = dialog.querySelector('#music-share-user-input');
-            const writeInput = dialog.querySelector('#music-share-write-input');
+            const userInput = /** @type {HTMLInputElement} */ (dialog.querySelector('#music-share-user-input'));
+            const writeInput = /** @type {HTMLInputElement} */ (dialog.querySelector('#music-share-write-input'));
             const userId = userInput.value.trim();
             if (!userId) return;
 
@@ -997,7 +1063,7 @@ const musicView = {
                         icon: 'fa-exclamation-circle',
                         iconClass: 'error',
                         title: i18n.t('music.error'),
-                        text: err.message
+                        text: /** @type {Error} */ (err).message
                     });
                 }
             }
@@ -1006,6 +1072,11 @@ const musicView = {
         this._loadSharesList(dialog);
     },
 
+    /**
+     *
+     * @param {HTMLDivElement} dialog
+     * @returns
+     */
     async _loadSharesList(dialog) {
         if (!this.currentPlaylist) return;
         const body = dialog.querySelector('.music-shares-body');
@@ -1019,6 +1090,7 @@ const musicView = {
                 headers: this._headers()
             });
             if (!resp.ok) throw new Error('Failed to load shares');
+            /** @type {Musicshare[]} */
             const shares = await resp.json();
 
             if (shares.length === 0) {
@@ -1040,16 +1112,22 @@ const musicView = {
 
             body.querySelectorAll('.music-share-remove-btn').forEach((btn) => {
                 btn.addEventListener('click', async () => {
-                    const item = btn.closest('.music-share-item');
+                    const item = /** @type {HTMLDivElement} */ (btn.closest('.music-share-item'));
                     const userId = item.dataset.userId;
                     await this._removeShare(userId, dialog);
                 });
             });
         } catch (err) {
-            body.innerHTML = `<p class="music-shares-empty">${this._escapeHtml(err.message)}</p>`;
+            body.innerHTML = `<p class="music-shares-empty">${this._escapeHtml(/** @type {Error} */ (err).message)}</p>`;
         }
     },
 
+    /**
+     *
+     * @param {string} userId
+     * @param {HTMLDivElement} dialog
+     * @returns
+     */
     async _removeShare(userId, dialog) {
         if (!this.currentPlaylist) return;
 
@@ -1067,7 +1145,7 @@ const musicView = {
                     icon: 'fa-exclamation-circle',
                     iconClass: 'error',
                     title: i18n.t('music.error'),
-                    text: err.message
+                    text: /** @type {Error} */ (err).message
                 });
             }
         }
@@ -1115,7 +1193,7 @@ const musicView = {
                     icon: 'fa-exclamation-circle',
                     iconClass: 'error',
                     title: i18n.t('music.error'),
-                    text: err.message
+                    text: /** @type {Error} */ (err).message
                 });
             }
         }
@@ -1183,7 +1261,7 @@ const musicView = {
                         icon: 'fa-exclamation-circle',
                         iconClass: 'error',
                         title: i18n.t('music.error'),
-                        text: err.message
+                        text: /** @type {Error} */ (err).message
                     });
                 }
             }
@@ -1198,10 +1276,15 @@ const musicView = {
  * Handles audio playback, queue, and controls
  */
 const musicPlayer = {
+    /** @type {HTMLAudioElement | null} */
     audio: null,
+
+    /** @type {PlaylistItem[]} */
     queue: [],
     currentIndex: -1,
+    /** @type {PlaylistItem|null} */
     currentTrack: null,
+
     isPlaying: false,
     volume: 0.7,
     isMuted: false,
@@ -1306,7 +1389,7 @@ const musicPlayer = {
         const shuffleBtn = document.getElementById('player-shuffle-btn');
         const repeatBtn = document.getElementById('player-repeat-btn');
         const progressBar = document.getElementById('player-progress-bar');
-        const volumeInput = document.getElementById('player-volume-input');
+        const volumeInput = /** @type {HTMLInputElement} */ (document.getElementById('player-volume-input'));
         const volBtn = document.getElementById('player-vol-btn');
         const playlistBtn = document.getElementById('player-playlist-btn');
         const closeQueueBtn = document.getElementById('player-close-queue-btn');
@@ -1338,7 +1421,8 @@ const musicPlayer = {
 
         if (volumeInput) {
             volumeInput.addEventListener('input', (e) => {
-                this.setVolume(e.target.value / 100);
+                const target = /** @type {HTMLInputElement} */ (e.target);
+                this.setVolume(parseFloat(target.value) / 100);
             });
         }
 
@@ -1381,12 +1465,22 @@ const musicPlayer = {
         document.body.classList.remove('music-player-active');
     },
 
+    /**
+     *
+     * @param {PlaylistItem[]} tracks
+     * @param {string} playlistName
+     */
     setQueue(tracks, playlistName = '') {
         this.queue = [...tracks];
         this.playlistName = playlistName;
         this._updateQueueUI();
     },
 
+    /**
+     *
+     * @param {number} index
+     * @returns
+     */
     playTrack(index) {
         if (index < 0 || index >= this.queue.length) return;
 
@@ -1488,15 +1582,19 @@ const musicPlayer = {
         }
     },
 
+    /**
+     *
+     * @param {number} vol
+     */
     setVolume(vol) {
         this.volume = Math.max(0, Math.min(1, vol));
         this.audio.volume = this.volume;
         this.isMuted = this.volume === 0;
         this._updateVolumeIcon();
 
-        const input = document.getElementById('player-volume-input');
+        const input = /** @type {HTMLInputElement} */ (document.getElementById('player-volume-input'));
         if (input) {
-            input.value = this.volume * 100;
+            input.value = String(this.volume * 100);
         }
     },
 
@@ -1522,6 +1620,11 @@ const musicPlayer = {
         btn.querySelector('i').className = `fas ${icon}`;
     },
 
+    /**
+     *
+     * @param {PointerEvent} e
+     * @returns
+     */
     _seek(e) {
         const bar = document.getElementById('player-progress-bar');
         if (!bar) return;
@@ -1596,6 +1699,10 @@ const musicPlayer = {
         this._updateUI();
     },
 
+    /**
+     *
+     * @param {ErrorEvent} e
+     */
     _onError(e) {
         console.error('Audio error:', e);
         this.isPlaying = false;
@@ -1624,7 +1731,8 @@ const musicPlayer = {
                 if (oxiIcon) {
                     icon.outerHTML = oxiIcon(iconName, extraClass);
                 } else {
-                    icon.className = `fas fa-${iconName} ${extraClass}`;
+                    icon.classList.remove(...icon.classList);
+                    icon.classList.add('fas', `fa-${iconName}`, `${extraClass}`);
                 }
             }
         }
@@ -1640,7 +1748,7 @@ const musicPlayer = {
         }
 
         if (musicView.currentTracks.length > 0) {
-            document.querySelectorAll('.music-track').forEach((row) => {
+            /** @type {NodeListOf<HTMLDivElement>} */ (document.querySelectorAll('.music-track')).forEach((row) => {
                 const idx = parseInt(row.dataset.idx, 10);
                 row.classList.toggle('playing', idx === this.currentIndex && this.isPlaying);
 
@@ -1710,15 +1818,16 @@ const musicPlayer = {
             )
             .join('');
 
-        queueList.querySelectorAll('.player-queue-item').forEach((item) => {
+        /** @type {NodeListOf<HTMLDivElement>} */ (queueList.querySelectorAll('.player-queue-item')).forEach((item) => {
             item.addEventListener('click', (e) => {
-                if (e.target.closest('.queue-item-remove')) return;
+                const target = /** @type {Element} */ (e.target);
+                if (target.closest('.queue-item-remove')) return;
                 const idx = parseInt(item.dataset.idx, 10);
                 this.playTrack(idx);
             });
         });
 
-        queueList.querySelectorAll('.queue-item-remove').forEach((btn) => {
+        /** @type {NodeListOf<HTMLButtonElement>} */ (queueList.querySelectorAll('.queue-item-remove')).forEach((btn) => {
             btn.addEventListener('click', (e) => {
                 e.stopPropagation();
                 const idx = parseInt(btn.dataset.idx, 10);
@@ -1727,6 +1836,10 @@ const musicPlayer = {
         });
     },
 
+    /**
+     *
+     * @param {number} idx
+     */
     _removeFromQueue(idx) {
         if (idx === this.currentIndex) {
             if (this.queue.length === 1) {
@@ -1754,6 +1867,10 @@ const musicPlayer = {
         this._updateUI();
     },
 
+    /**
+     *
+     * @param {boolean|undefined} [show]
+     */
     _toggleQueue(show) {
         const queue = document.getElementById('player-queue');
         if (queue) {
@@ -1765,6 +1882,11 @@ const musicPlayer = {
         }
     },
 
+    /**
+     *
+     * @param {number|null} secs
+     * @returns {String}
+     */
     _formatTime(secs) {
         if (!secs || Number.isNaN(secs)) return '0:00';
         const mins = Math.floor(secs / 60);
@@ -1772,10 +1894,19 @@ const musicPlayer = {
         return `${mins}:${s.toString().padStart(2, '0')}`;
     },
 
+    /**
+     *
+     * @param {number|null} secs
+     * @returns {String}
+     */
     _formatDuration(secs) {
         return this._formatTime(secs);
     },
 
+    /**
+     * @param {string|null} str
+     * @returns {String}
+     */
     _escapeHtml(str) {
         if (!str) return '';
         return str.replace(/&/g, '&amp;').replace(/</g, '&lt;').replace(/>/g, '&gt;').replace(/"/g, '&quot;');
diff --git a/static/js/features/library/photos.js b/static/js/features/library/photos.js
index 4d506458..eff922ba 100644
--- a/static/js/features/library/photos.js
+++ b/static/js/features/library/photos.js
@@ -8,10 +8,14 @@ import { i18n } from '../../core/i18n.js';
 import { thumbnail } from '../thumbnail.js';
 import { photosLightbox } from './photosLightbox.js';
 
-/** @import {FileInfo} from '../../core/types.js' */
+/** @import {FileItem} from '../../core/types.js' */
+
+/**
+ * @typedef {'daily'|'monthly'|'yearly'} PhotoModeEnum
+ */
 
 const photosView = {
-    /** @type {Array} All loaded photo items */
+    /** @type {Array<FileItem>} All loaded photo items */
     items: [],
     /** @type {string|null} Cursor for next page */
     nextCursor: null,
@@ -27,7 +31,7 @@ const photosView = {
     _container: null,
     /** @type {boolean} */
     _initialized: false,
-    /** @type {'daily'|'monthly'|'yearly'} */
+    /** @type {PhotoModeEnum} */
     groupMode: 'monthly',
     /** @type {Map<string, string>} fileId → thumbnail URL (persists across re-renders) */
     _videoThumbCache: new Map(),
@@ -84,6 +88,11 @@ const photosView = {
     },
 
     /** Switch grouping mode */
+    /**
+     *
+     * @param {PhotoModeEnum} mode
+     * @returns
+     */
     setGroupMode(mode) {
         if (this.groupMode === mode) return;
         this.groupMode = mode;
@@ -112,6 +121,7 @@ const photosView = {
 
             if (!res.ok) throw new Error(`HTTP ${res.status}`);
 
+            /** @type {FileItem[]} */
             const data = await res.json();
 
             if (!data || data.length === 0) {
@@ -178,7 +188,9 @@ const photosView = {
 
     /** Append-only render for infinite scroll — inserts only the items
      *  from this.items[startIndex..] without destroying existing DOM.
-     *  Complexity: O(batch) instead of O(total_items). */
+     *  Complexity: O(batch) instead of O(total_items).
+     * @param {number} startIndex
+     */
     _appendBatch(startIndex) {
         if (!this._container) return;
         this._destroyObserver();
@@ -227,7 +239,10 @@ const photosView = {
         this._setupVideoThumbnails(startIndex);
     },
 
-    /** Generate HTML for a single photo/video tile */
+    /**
+     * Generate HTML for a single photo/video tile
+     * @param {FileItem} file
+     */
     _renderTile(file) {
         const isVideo = file.mime_type?.startsWith('video/');
         const selected = this.selected.has(file.id) ? ' selected' : '';
@@ -266,7 +281,7 @@ const photosView = {
     /** @param {number} [startIndex=0] When > 0, only process video tiles
      *  for items[startIndex..] — avoids re-scanning the entire DOM. */
     _setupVideoThumbnails(startIndex = 0) {
-        const tiles = /** @type {NodeListOf<HTMLDivElement> */ (this._container?.querySelectorAll('.photo-tile[data-mime^="video/"]'));
+        const tiles = /** @type {NodeListOf<HTMLDivElement>} */ (this._container?.querySelectorAll('.photo-tile[data-mime^="video/"]'));
         const newIds = startIndex > 0 ? new Set(this.items.slice(startIndex).map((f) => f.id)) : null;
 
         if (!tiles) return;
@@ -290,11 +305,15 @@ const photosView = {
         }
     },
 
-    /** Extract a frame and upload all thumbnail sizes via thumbnail.queueGenerate(). */
+    /**
+     * Extract a frame and upload all thumbnail sizes via thumbnail.queueGenerate().
+     * @param {HTMLDivElement} tile
+     * @param {HTMLImageElement} img
+     */
     async _generateVideoThumbnail(tile, img) {
         const fileId = tile.dataset.id;
         // TODO: remove this HACK, this is not evolutive...
-        const file = /** @type {FileInfo} */ ({ id: fileId, icon_special_class: 'video-icon', name: tile.dataset.name, mime_type: tile.dataset.mime });
+        const file = /** @type {FileItem} */ ({ id: fileId, icon_special_class: 'video-icon', name: tile.dataset.name, mime_type: tile.dataset.mime });
 
         try {
             await thumbnail.queueGenerate(file, null, (previewDataUrl) => {
@@ -335,7 +354,10 @@ const photosView = {
             </div>`;
     },
 
-    /** Group items by the current groupMode */
+    /**
+     *  Group items by the current groupMode
+     * @param {FileItem[]} items
+     */
     _groupItems(items) {
         const map = new Map();
         for (const item of items) {
@@ -363,20 +385,24 @@ const photosView = {
         return map;
     },
 
-    /** Handle click on photo tile or toolbar */
+    /**
+     * Handle click on photo tile or toolbar
+     * @param {MouseEvent} e
+     */
     _handleClick(e) {
         // Handle group mode toggle
-        const modeBtn = e.target.closest('[data-group-mode]');
+        const target = /** @type {Element} */ (e.target);
+        const modeBtn = /** @type {HTMLButtonElement} */ (target.closest('[data-group-mode]'));
         if (modeBtn) {
-            this.setGroupMode(modeBtn.dataset.groupMode);
+            this.setGroupMode(/** @type {PhotoModeEnum} */ (modeBtn.dataset.groupMode));
             return;
         }
 
-        const tile = e.target.closest('.photo-tile');
+        const tile = /** @type {HTMLDivElement} */ (target.closest('.photo-tile'));
         if (!tile) return;
 
         const id = tile.dataset.id;
-        const check = e.target.closest('.photo-check');
+        const check = target.closest('.photo-check');
 
         // If clicking checkbox or in selection mode, toggle select
         if (check || this.selected.size > 0) {
@@ -391,7 +417,11 @@ const photosView = {
         }
     },
 
-    /** Toggle selection of an item */
+    /**
+     * Toggle selection of an item
+     * @param {string} id
+     * @param {HTMLDivElement} tile
+     */
     _toggleSelect(id, tile) {
         if (this.selected.has(id)) {
             this.selected.delete(id);
@@ -483,6 +513,7 @@ const photosView = {
         if (bar) bar.style.display = 'none';
     },
 
+    /** @param {boolean} show */
     _showLoading(show) {
         if (!this._container) return;
         let loader = this._container.querySelector('.photos-loading');
@@ -503,12 +534,14 @@ const photosView = {
         }
     },
 
+    /** @param {any} s */
     _escHtml(s) {
         const d = document.createElement('div');
         d.textContent = s;
         return d.innerHTML;
     },
 
+    /** @param {any} s */
     _escAttr(s) {
         return String(s || '')
             .replace(/"/g, '&quot;')
diff --git a/static/js/features/library/photosLightbox.js b/static/js/features/library/photosLightbox.js
index c21e73d9..2dc58076 100644
--- a/static/js/features/library/photosLightbox.js
+++ b/static/js/features/library/photosLightbox.js
@@ -6,8 +6,11 @@
 import { getCsrfHeaders } from '../../core/csrf.js';
 import { favorites } from '../library/favorites.js';
 
+/** @import {FileItem, FileMetadata} from '../../core/types.js' */
+/** @typedef {typeof import('./photos.js').photosView} PhotosView */
+
 export const photosLightbox = {
-    /** @type {Array} Items array reference */
+    /** @type {Array<FileItem>} Items array reference */
     items: [],
     /** @type {number} Current index */
     index: -1,
@@ -15,14 +18,14 @@ export const photosLightbox = {
     _overlay: null,
     /** @type {string|null} Current blob URL to revoke */
     _blobUrl: null,
-    /** @type {Function|null} */
+    /** @type {(ev: KeyboardEvent) => any|null} */
     _keyHandler: null,
-    /** @type {Object|null} Reference to photosView, set after both modules load */
+    /** @type {PhotosView|null} Reference to photosView, set after both modules load */
     _photosView: null,
 
     /**
      * Register the photosView reference (called from photos.js to avoid circular imports).
-     * @param {Object} pv
+     * @param {any} pv
      */
     setPhotosView(pv) {
         this._photosView = pv;
@@ -33,7 +36,11 @@ export const photosLightbox = {
         return getCsrfHeaders();
     },
 
-    /** Open lightbox at given index */
+    /**
+     * Open lightbox at given index
+     * @param {FileItem[]} items
+     * @param {number} index
+     */
     open(items, index) {
         this.items = items;
         this.index = index;
@@ -99,21 +106,21 @@ export const photosLightbox = {
         this._overlay = el;
 
         // Event listeners
-        el.querySelector('.lightbox-close').onclick = () => this.close();
-        el.querySelector('.lightbox-prev').onclick = () => this.prev();
-        el.querySelector('.lightbox-next').onclick = () => this.next();
+        /** @type {HTMLButtonElement} */ (el.querySelector('.lightbox-close')).onclick = () => this.close();
+        /** @type {HTMLButtonElement} */ (el.querySelector('.lightbox-prev')).onclick = () => this.prev();
+        /** @type {HTMLButtonElement} */ (el.querySelector('.lightbox-next')).onclick = () => this.next();
 
         // Click backdrop to close
         el.addEventListener('click', (e) => {
-            if (e.target === el || e.target.classList.contains('lightbox-content')) {
+            if (e.target === el || /** @type {HTMLElement} */ (e.target).classList.contains('lightbox-content')) {
                 this.close();
             }
         });
 
         // Toolbar actions
-        el.querySelector('.lb-download').onclick = () => this._download();
-        el.querySelector('.lb-favorite').onclick = () => this._toggleFavorite();
-        el.querySelector('.lb-delete').onclick = () => this._delete();
+        /** @type {HTMLButtonElement} */ (el.querySelector('.lb-download')).onclick = () => this._download();
+        /** @type {HTMLButtonElement} */ (el.querySelector('.lb-favorite')).onclick = () => this._toggleFavorite();
+        /** @type {HTMLButtonElement} */ (el.querySelector('.lb-delete')).onclick = () => this._delete();
 
         // Animate in
         requestAnimationFrame(() => el.classList.add('active'));
@@ -144,8 +151,8 @@ export const photosLightbox = {
         meta.textContent = `${dateStr} · ${item.size_formatted || ''}`;
 
         // Update nav button visibility
-        this._overlay.querySelector('.lightbox-prev').style.visibility = this.index > 0 ? 'visible' : 'hidden';
-        this._overlay.querySelector('.lightbox-next').style.visibility = this.index < this.items.length - 1 ? 'visible' : 'hidden';
+        /** @type {HTMLButtonElement} */ (this._overlay.querySelector('.lightbox-prev')).classList.toggle('hidden', !(this.index > 0));
+        /** @type {HTMLButtonElement} */ (this._overlay.querySelector('.lightbox-next')).classList.toggle('hidden', !(this.index < this.items.length - 1));
 
         // Load content
         this._revokeBlob();
@@ -176,7 +183,13 @@ export const photosLightbox = {
         this._loadMetadata(item.id, meta, dateStr, item.size_formatted || '');
     },
 
-    /** Load EXIF metadata for info bar */
+    /**
+     * Load EXIF metadata for info bar
+     * @param {string} fileId
+     * @param {Element} metaEl
+     * @param {string} dateStr
+     * @param {string} sizeStr
+     */
     async _loadMetadata(fileId, metaEl, dateStr, sizeStr) {
         try {
             const res = await fetch(`/api/files/${fileId}/metadata`, {
@@ -184,16 +197,18 @@ export const photosLightbox = {
                 headers: this._headers()
             });
             if (res.ok) {
-                const data = await res.json();
+                const metadata = /** @type {FileMetadata} */ (await res.json());
                 const parts = [dateStr];
                 if (sizeStr) parts.push(sizeStr);
-                if (data.camera_make || data.camera_model) {
-                    parts.push([data.camera_make, data.camera_model].filter(Boolean).join(' '));
+                if (metadata.camera_make || metadata.camera_model) {
+                    parts.push([metadata.camera_make, metadata.camera_model].filter(Boolean).join(' '));
                 }
-                if (data.width && data.height) {
-                    parts.push(`${data.width}×${data.height}`);
+                if (metadata.width && metadata.height) {
+                    parts.push(`${metadata.width}×${metadata.height}`);
                 }
                 metaEl.textContent = parts.join(' · ');
+
+                //TODO: add geoloc pointer to openstreetmap ?
             }
         } catch (_err) {
             // Non-critical, keep existing meta
@@ -220,7 +235,7 @@ export const photosLightbox = {
             await fetch(`/api/favorites/file/${item.id}`, {
                 method: 'POST',
                 credentials: 'include',
-                headers: this._headers(true)
+                headers: this._headers()
             });
             const btn = this._overlay.querySelector('.lb-favorite');
             if (btn) {
@@ -254,11 +269,11 @@ export const photosLightbox = {
             this.items.splice(this.index, 1);
             if (this.items.length === 0) {
                 this.close();
-                if (this._photosView) this._photosView._render();
+                if (this._photosView) this._photosView._renderFull(); // will call renderEmpty() on this case
             } else {
                 if (this.index >= this.items.length) this.index = this.items.length - 1;
                 this._show();
-                if (this._photosView) this._photosView._render();
+                if (this._photosView) this._photosView._renderFull();
             }
         } catch (err) {
             console.error('Delete failed:', err);
@@ -289,6 +304,7 @@ export const photosLightbox = {
         }
     },
 
+    /** @param {any} s */
     _escAttr(s) {
         return String(s || '')
             .replace(/"/g, '&quot;')
diff --git a/static/js/features/library/recent.js b/static/js/features/library/recent.js
index ad4b833b..ccd207be 100644
--- a/static/js/features/library/recent.js
+++ b/static/js/features/library/recent.js
@@ -12,6 +12,8 @@ import { i18n } from '../../core/i18n.js';
 import { multiSelect } from '../files/multiSelect.js';
 import * as pathTooltip from '../pathTooltip.js';
 
+/** @import {FileItem, FolderItem, ItemTypeEnum} from '../../core/types.js' */
+
 const recent = {
     /** Maximum items to request from the server */
     MAX_RECENT_FILES: 20,
@@ -38,8 +40,9 @@ const recent = {
      */
     setupEventListeners() {
         document.addEventListener('file-accessed', (event) => {
-            if (event.detail?.file) {
-                const file = event.detail.file;
+            const e = /** @type {CustomEvent} */ (event);
+            if (e.detail?.file) {
+                const file = e.detail.file;
                 const itemType = file.item_type || 'file';
                 this._recordAccess(file.id, itemType);
             }
@@ -48,6 +51,8 @@ const recent = {
 
     /**
      * Record an access event on the server.
+     * @param {string} itemId
+     * @param {ItemTypeEnum} itemType
      */
     async _recordAccess(itemId, itemType) {
         try {
@@ -120,8 +125,12 @@ const recent = {
                 `);
             }
 
+            /** @type {FolderItem[]} */
             const folders = [];
+
+            /** @type {FileItem[]} */
             const files = [];
+
             for (const item of recentItems) {
                 const isFolder = item.item_type === 'folder';
                 if (isFolder) {
@@ -130,7 +139,13 @@ const recent = {
                         name: item.item_name || item.item_id,
                         parent_id: item.parent_id || '',
                         modified_at: item.accessed_at,
-                        path: item.item_path || ''
+                        path: item.item_path || '',
+                        category: 'folder',
+                        created_at: item.created_at,
+                        icon_class: '',
+                        icon_special_class: '',
+                        owner_id: '',
+                        is_root: false
                     });
                 } else {
                     files.push({
@@ -144,7 +159,10 @@ const recent = {
                         size: item.item_size || 0,
                         size_formatted: item.size_formatted,
                         modified_at: item.accessed_at,
-                        path: item.item_path || ''
+                        path: item.item_path || '',
+                        owner_id: '',
+                        created_at: item.created_at,
+                        sort_date: item.created_at
                     });
                 }
             }
diff --git a/static/js/features/pathTooltip.js b/static/js/features/pathTooltip.js
index 4af11ab6..743f824b 100644
--- a/static/js/features/pathTooltip.js
+++ b/static/js/features/pathTooltip.js
@@ -38,7 +38,13 @@ function _onLeave() {
     _tooltip?.classList.add('hidden');
 }
 
-/** @type {WeakMap<HTMLElement, {enter: Function, leave: Function}>} */
+/**
+ * @typedef {Object} EnterLeaveF
+ * @property {(e: MouseEvent) => void} enter
+ * @property {(e: MouseEvent) => void} leave
+ *
+
+/** @type {WeakMap<HTMLElement, EnterLeaveF>} */
 const _listeners = new WeakMap();
 
 /**
@@ -49,10 +55,15 @@ function init(container) {
     const items = container.querySelectorAll('.file-item[data-path]');
     items.forEach((item) => {
         const el = /** @type {HTMLElement} */ (item);
+
+        /** @type {(e: MouseEvent) => void} */
         const enter = (e) => _onEnter(e);
-        const leave = () => _onLeave();
         el.addEventListener('mouseenter', enter);
+
+        /** @type {(e: MouseEvent) => void} */
+        const leave = (_e) => _onLeave();
         el.addEventListener('mouseleave', leave);
+
         _listeners.set(el, { enter, leave });
     });
 }
diff --git a/static/js/features/sharing/fileSharing.js b/static/js/features/sharing/fileSharing.js
index 150b8734..fd54d0e8 100644
--- a/static/js/features/sharing/fileSharing.js
+++ b/static/js/features/sharing/fileSharing.js
@@ -9,6 +9,10 @@ import { ui } from '../../app/ui.js';
 import { getCsrfHeaders } from '../../core/csrf.js';
 import { formatDateTime } from '../../core/formatters.js';
 
+/**
+ * @import {CreateShare, ShareItem, UpdateShare} from '../../core/types.js'
+ */
+
 const fileSharing = {
     /** Auth header helper — tokens are in HttpOnly cookies now */
     _headers(json = true) {
@@ -21,16 +25,17 @@ const fileSharing = {
      * Create a shared link via backend API
      * @param {string} itemId - ID of the file or folder
      * @param {string} itemType - 'file' or 'folder'
-     * @param {Object} options - { name, password, expirationDate, permissions }
+     * @param {CreateShare} [options] -
      * @returns {Promise<Object>} ShareDto from backend
      */
-    async createSharedLink(itemId, itemType, options = {}) {
+    // FIXME unused ?? duplicate with createSharedLink() from contextMenu
+    async createSharedLink(itemId, itemType, options) {
         const body = {
             item_id: itemId,
-            item_name: options.name || null,
+            item_name: options.item_name || null,
             item_type: itemType,
             password: options.password || null,
-            expires_at: options.expirationDate ? Math.floor(new Date(options.expirationDate).getTime() / 1000) : null,
+            expires_at: options.expires_at ? Math.floor(new Date(options.expires_at).getTime() / 1000) : null,
             permissions: options.permissions || {
                 read: true,
                 write: false,
@@ -54,7 +59,7 @@ const fileSharing = {
 
     /**
      * Get all shared links for the current user
-     * @returns {Promise<Array>} Array of ShareDto
+     * @returns {Promise<ShareItem[]>} Array of ShareDto
      */
     async getSharedLinks() {
         try {
@@ -62,7 +67,7 @@ const fileSharing = {
                 headers: this._headers(false)
             });
             if (!res.ok) return [];
-            const data = await res.json();
+            const data = /** @type {ShareItem[]} */ await res.json();
             return data.items || [];
         } catch (error) {
             console.error('Error fetching shared links:', error);
@@ -74,7 +79,7 @@ const fileSharing = {
      * Get shared links for a specific item (server-side filtered)
      * @param {string} itemId
      * @param {string} itemType - 'file' or 'folder'
-     * @returns {Promise<Array>} Shares for this item
+     * @returns {Promise<ShareItem[]>} Shares for this item
      */
     async getSharedLinksForItem(itemId, itemType) {
         try {
@@ -96,6 +101,8 @@ const fileSharing = {
 
     /**
      * Check if an item has any shared links
+     * @param {string} itemId
+     * @param {string} itemType
      * @returns {Promise<boolean>}
      */
     async hasSharedLinks(itemId, itemType) {
@@ -106,7 +113,7 @@ const fileSharing = {
     /**
      * Update a shared link
      * @param {string} shareId
-     * @param {Object} updateData - { permissions, password, expires_at }
+     * @param {UpdateShare} updateData - { permissions, password, expires_at }
      * @returns {Promise<Object>} Updated ShareDto
      */
     async updateSharedLink(shareId, updateData) {
diff --git a/static/js/features/thumbnail.js b/static/js/features/thumbnail.js
index ef924012..0d8c3a0d 100644
--- a/static/js/features/thumbnail.js
+++ b/static/js/features/thumbnail.js
@@ -1,8 +1,11 @@
 import { getCsrfHeaders } from '../core/csrf.js';
 
-/** @import {FileInfo} from '../core/types.js' */
+/** @import {FileItem} from '../core/types.js' */
 
-/** @type {typeof import('../vendors/pdf.min.d.ts') | null} */
+/**
+ * use any type so tsc will not scan library
+ * @type {any}
+ */
 let _pdfjsLib = null;
 
 // TODO: do we need to add a max concurrncy ?
@@ -10,11 +13,13 @@ let _pdfjsLib = null;
 /**
  * Lazy-loads pdf.min.mjs on first use via dynamic import so it is never
  * bundled into the IIFE (it uses top-level await which breaks IIFE wrapping).
- * @returns {Promise<typeof import('../vendors/pdf.min.d.ts')>}
+ * @returns {Promise<any>}
  */
 async function getPdfjsLib() {
     if (_pdfjsLib) return _pdfjsLib;
-    _pdfjsLib = await import('/js/vendors/pdf.min.mjs');
+    // IMPORTANT: this hack (const lib=...) so tsc will not load vendors library
+    const lib = '../vendors/pdf.min.mjs';
+    _pdfjsLib = /** @type {any} */ (await import(lib));
     _pdfjsLib.GlobalWorkerOptions.workerSrc = '/js/vendors/pdf.worker.min.mjs';
     return _pdfjsLib;
 }
@@ -23,7 +28,7 @@ export const thumbnail = {
     SUPPORTED_MIME_TYPE: [/^image\//, /^application\/pdf$/, /^video\//],
     /**
      *
-     * @param {Object} file
+     * @param {FileItem} file
      * @returns {boolean}
      */
     canHandle(file) {
@@ -109,7 +114,7 @@ export const thumbnail = {
 
     /**
      *
-     * @param {FileInfo} file
+     * @param {FileItem} file
      * @param {string} source
      * @returns {Promise<ImageBitmap>}
      *
@@ -163,7 +168,7 @@ export const thumbnail = {
     /**
      * generateThumbnail and update image
      *
-     * @param {Object} file the source of the image
+     * @param {FileItem} file the source of the image
      * @param {((dataURL: string) => void) | null} [onIconGenerated] the callback once thumbnail is generated
      * @param {((dataURL: string) => void) | null} [onPreviewGenerated] the callback once thumbnail is generated
      *
@@ -203,7 +208,7 @@ export const thumbnail = {
 
     MAX_CONCURRENT: 3,
     _activeGenerates: 0,
-    /** @type {Array<() => void>} */
+    /** @type {Array<(resolve: any) => void>} */
     _generateQueue: [],
 
     /**
@@ -211,7 +216,7 @@ export const thumbnail = {
      * At most MAX_CONCURRENT generations run simultaneously; excess calls are
      * queued and resume automatically as slots free up.
      *
-     * @param {FileInfo} file
+     * @param {FileItem} file
      * @param {((dataURL: string) => void) | null} [onIconGenerated]
      * @param {((dataURL: string) => void) | null} [onPreviewGenerated]
      * @returns {Promise<void>}
@@ -224,7 +229,7 @@ export const thumbnail = {
         try {
             await this._generate(file, onIconGenerated, onPreviewGenerated);
         } catch (err) {
-            if (err instanceof Event) {
+            if (err instanceof Event && 'error' in err.target) {
                 console.warn(`generation of thumbnail for ${file.name} failed: `, err.target.error);
             } else if (err instanceof Error) {
                 console.warn(`generation of thumbnail for ${file.name} failed: `, err.message);
diff --git a/static/js/vendors/pdf.min.d.ts b/static/js/vendors/pdf.min.d.ts
new file mode 100644
index 00000000..c5430900
--- /dev/null
+++ b/static/js/vendors/pdf.min.d.ts
@@ -0,0 +1,4 @@
+declare module '*pdf.min.mjs' {
+    const pdfjsLib: any;
+    export = pdfjsLib;
+}
diff --git a/static/js/vendors/vendors.d.ts b/static/js/vendors/vendors.d.ts
new file mode 100644
index 00000000..d55b5a83
--- /dev/null
+++ b/static/js/vendors/vendors.d.ts
@@ -0,0 +1,5 @@
+declare module '*.mjs' {
+  const value: any;
+  export default value;
+}
+
diff --git a/static/js/views/admin/admin.js b/static/js/views/admin/admin.js
index 49e487d2..3e0b92ed 100644
--- a/static/js/views/admin/admin.js
+++ b/static/js/views/admin/admin.js
@@ -3,13 +3,20 @@ import { escapeHtml } from '../../core/formatters.js';
 import { i18n } from '../../core/i18n.js';
 import { oxiIconsInit } from '../../core/icons.js';
 
+/**
+ * @import {RoleEnum} from '../../core/types.js'
+ */
+
 const API = '/api';
 let currentAdminId = '';
 let usersPage = 0;
 const PAGE_SIZE = 50;
 let totalUsers = 0;
 
-/** Escape a string for safe embedding inside a JS string literal within an HTML attribute. */
+/**
+ * Escape a string for safe embedding inside a JS string literal within an HTML attribute.
+ * @param {string} s
+ */
 function _escJs(s) {
     if (typeof s !== 'string') return '';
     return s.replace(/[^\w .-]/g, (c) => {
@@ -17,6 +24,7 @@ function _escJs(s) {
     });
 }
 
+/** @param {string} id */
 function hideElement(id) {
     const element = document.getElementById(id);
     if (!element) return;
@@ -24,6 +32,10 @@ function hideElement(id) {
     element.classList.add('hidden');
 }
 
+/**
+ * @param {string} id
+ * @param {string} [mode]
+ */
 function showElement(id, mode = 'block') {
     const element = document.getElementById(id);
     if (!element) return;
@@ -39,6 +51,7 @@ function headers() {
     return { 'Content-Type': 'application/json', ...getCsrfHeaders() };
 }
 
+/** @param {number} bytes */
 function formatBytes(bytes) {
     if (bytes === 0) return '0 B';
     const k = 1024,
@@ -47,11 +60,12 @@ function formatBytes(bytes) {
     return `${parseFloat((bytes / k ** i).toFixed(1))} ${sizes[i]}`;
 }
 
+/** @param {string|null} dateStr */
 function timeAgo(dateStr) {
     if (!dateStr) return i18n.t('admin.never');
     const d = new Date(dateStr);
     const now = new Date();
-    const secs = Math.floor((now - d) / 1000);
+    const secs = Math.floor((now.getTime() - d.getTime()) / 1000);
     if (secs < 60) return i18n.t('admin.just_now');
     if (secs < 3600) return i18n.t('admin.minutes_ago', { n: Math.floor(secs / 60) });
     if (secs < 86400) return i18n.t('admin.hours_ago', { n: Math.floor(secs / 3600) });
@@ -60,6 +74,7 @@ function timeAgo(dateStr) {
 }
 
 /* ── Custom confirm modal ── */
+/** @param {string} message */
 function showConfirm(message) {
     return new Promise((resolve) => {
         const overlay = document.getElementById('confirm-modal');
@@ -70,6 +85,7 @@ function showConfirm(message) {
         overlay.classList.remove('hidden');
         overlay.classList.add('show-flex');
 
+        /** @param {any} result */
         function cleanup(result) {
             overlay.classList.remove('show-flex');
             overlay.classList.add('hidden');
@@ -84,6 +100,7 @@ function showConfirm(message) {
         function onNo() {
             cleanup(false);
         }
+        /** @param {Event} e */
         function onOverlay(e) {
             if (e.target === overlay) cleanup(false);
         }
@@ -96,6 +113,10 @@ function showConfirm(message) {
 /* ── Tab switching with fade animation ── */
 let activeTabName = 'dashboard';
 
+/**
+ * @param {string} name
+ * @param {Element|undefined} el
+ */
 function switchTab(name, el) {
     if (name === activeTabName) return;
     var oldTab = document.getElementById(`tab-${activeTabName}`);
@@ -158,7 +179,7 @@ async function loadDashboard() {
         document.getElementById('ds-quotas-flag').textContent = d.quotas_enabled ? i18n.t('admin.enabled') : i18n.t('admin.disabled');
 
         if (typeof d.registration_enabled !== 'undefined') {
-            document.getElementById('ds-registration').checked = d.registration_enabled;
+            /** @type {HTMLInputElement} */ (document.getElementById('ds-registration')).checked = d.registration_enabled;
             if (d.registration_enabled) hideElement('registration-warning');
             else showElement('registration-warning', 'flex');
         }
@@ -200,7 +221,7 @@ async function loadUsers() {
         }
 
         tbody.innerHTML = users
-            .map((u) => {
+            .map((/** @type {any} */ u) => {
                 const quotaPct = u.storage_quota_bytes > 0 ? (u.storage_used_bytes / u.storage_quota_bytes) * 100 : 0;
                 const quotaColor = quotaPct > 90 ? 'red' : quotaPct > 70 ? 'orange' : 'green';
                 const quotaText =
@@ -306,18 +327,18 @@ async function loadUsers() {
             .join('');
 
         // Set dynamic progress bar widths (CSP-safe via JS property)
-        document.querySelectorAll('.progress-fill[data-width]').forEach((el) => {
+        /** @type {NodeListOf<HTMLDivElement>} */ (document.querySelectorAll('.progress-fill[data-width]')).forEach((el) => {
             el.style.width = `${el.dataset.width}%`;
             el.removeAttribute('data-width');
         });
 
         // Wire up admin action buttons (replaces inline onclick handlers)
-        document.querySelectorAll('.admin-action-btn').forEach((btn) => {
+        /** @type {NodeListOf<HTMLButtonElement>} */ (document.querySelectorAll('.admin-action-btn')).forEach((btn) => {
             btn.addEventListener('click', () => {
                 const action = btn.dataset.action;
                 if (action === 'quota') openQuotaModal(btn.dataset.uid, btn.dataset.uname, Number(btn.dataset.quota));
                 else if (action === 'reset-pw') openResetPasswordModal(btn.dataset.uid, btn.dataset.uname);
-                else if (action === 'toggle-role') toggleRole(btn.dataset.uid, btn.dataset.role);
+                else if (action === 'toggle-role') toggleRole(btn.dataset.uid, /** @type {RoleEnum} */ (btn.dataset.role));
                 else if (action === 'toggle-active') toggleActive(btn.dataset.uid, btn.dataset.active === 'true');
                 else if (action === 'delete') deleteUser(btn.dataset.uid, btn.dataset.uname);
             });
@@ -326,12 +347,12 @@ async function loadUsers() {
         const from = usersPage * PAGE_SIZE + 1;
         const to = Math.min((usersPage + 1) * PAGE_SIZE, totalUsers);
         document.getElementById('users-info').textContent = i18n.t('admin.showing_users', { from: from, to: to, total: totalUsers });
-        document.getElementById('prev-btn').disabled = usersPage === 0;
-        document.getElementById('next-btn').disabled = (usersPage + 1) * PAGE_SIZE >= totalUsers;
+        /** @type {HTMLButtonElement} */ (document.getElementById('prev-btn')).disabled = usersPage === 0;
+        /** @type {HTMLButtonElement} */ (document.getElementById('next-btn')).disabled = (usersPage + 1) * PAGE_SIZE >= totalUsers;
     } catch (e) {
         tbody.innerHTML =
             '<tr><td colspan="7" class="table-status-error"><i class="fas fa-exclamation-circle"></i> ' +
-            escapeHtml(i18n.t('admin.error_network', { message: e.message })) +
+            escapeHtml(i18n.t('admin.error_network', { message: /** @type {Error} */ (e).message })) +
             '</td></tr>';
     }
 }
@@ -349,6 +370,10 @@ function nextPage() {
     }
 }
 
+/**
+ * @param {string} userId
+ * @param {RoleEnum} currentRole
+ */
 async function toggleRole(userId, currentRole) {
     const newRole = currentRole === 'admin' ? 'user' : 'admin';
     const ok = await showConfirm(i18n.t('admin.confirm_role_change', { role: newRole }));
@@ -366,10 +391,14 @@ async function toggleRole(userId, currentRole) {
             alert(e.message || i18n.t('admin.error_generic'));
         }
     } catch (e) {
-        alert(i18n.t('admin.error_network', { message: e.message }));
+        alert(i18n.t('admin.error_network', { message: /** @type {Error} */ (e).message }));
     }
 }
 
+/**
+ * @param {string} userId
+ * @param {boolean} currentActive
+ */
 async function toggleActive(userId, currentActive) {
     const msg = currentActive ? i18n.t('admin.confirm_deactivate') : i18n.t('admin.confirm_activate');
     const ok = await showConfirm(msg);
@@ -387,10 +416,14 @@ async function toggleActive(userId, currentActive) {
             alert(e.message || i18n.t('admin.error_generic'));
         }
     } catch (e) {
-        alert(i18n.t('admin.error_network', { message: e.message }));
+        alert(i18n.t('admin.error_network', { message: /** @type {Error} */ (e).message }));
     }
 }
 
+/**
+ * @param {string} userId
+ * @param {string} username
+ */
 async function deleteUser(userId, username) {
     const ok = await showConfirm(i18n.t('admin.confirm_delete_user', { name: username }));
     if (!ok) return;
@@ -408,17 +441,22 @@ async function deleteUser(userId, username) {
             alert(e.message || i18n.t('admin.error_generic'));
         }
     } catch (e) {
-        alert(i18n.t('admin.error_network', { message: e.message }));
+        alert(i18n.t('admin.error_network', { message: /** @type {Error} */ (e).message }));
     }
 }
 
 let quotaUserId = '';
+/**
+ * @param {string} userId
+ * @param {string} username
+ * @param {number} currentQuota
+ */
 function openQuotaModal(userId, username, currentQuota) {
     quotaUserId = userId;
     document.getElementById('qm-username').textContent = username;
     const gb = currentQuota / 1073741824;
-    document.getElementById('qm-unit').value = '1073741824';
-    document.getElementById('qm-value').value = gb > 0 ? Math.round(gb * 10) / 10 : 0;
+    /** @type {HTMLInputElement} */ (document.getElementById('qm-unit')).value = '1073741824';
+    /** @type {HTMLInputElement} */ (document.getElementById('qm-value')).value = String(gb > 0 ? Math.round(gb * 10) / 10 : 0);
     showElement('quota-modal', 'flex');
 }
 function closeQuotaModal() {
@@ -426,8 +464,8 @@ function closeQuotaModal() {
 }
 
 async function saveQuota() {
-    const val = parseFloat(document.getElementById('qm-value').value) || 0;
-    const unit = parseInt(document.getElementById('qm-unit').value, 10);
+    const val = parseFloat(/** @type {HTMLInputElement} */ (document.getElementById('qm-value')).value) || 0;
+    const unit = parseInt(/** @type {HTMLInputElement} */ (document.getElementById('qm-unit')).value, 10);
     const bytes = Math.round(val * unit);
     try {
         const resp = await fetch(`${API}/admin/users/${quotaUserId}/quota`, {
@@ -445,33 +483,33 @@ async function saveQuota() {
             alert(e.message || i18n.t('admin.error_generic'));
         }
     } catch (e) {
-        alert(i18n.t('admin.error_network', { message: e.message }));
+        alert(i18n.t('admin.error_network', { message: /** @type {Error} */ (e).message }));
     }
 }
 
 function openCreateUserModal() {
-    document.getElementById('cu-username').value = '';
-    document.getElementById('cu-password').value = '';
-    document.getElementById('cu-email').value = '';
-    document.getElementById('cu-role').value = 'user';
-    document.getElementById('cu-quota-value').value = '1';
-    document.getElementById('cu-quota-unit').value = '1073741824';
+    /** @type {HTMLInputElement} */ (document.getElementById('cu-username')).value = '';
+    /** @type {HTMLInputElement} */ (document.getElementById('cu-password')).value = '';
+    /** @type {HTMLInputElement} */ (document.getElementById('cu-email')).value = '';
+    /** @type {HTMLInputElement} */ (document.getElementById('cu-role')).value = 'user';
+    /** @type {HTMLInputElement} */ (document.getElementById('cu-quota-value')).value = '1';
+    /** @type {HTMLInputElement} */ (document.getElementById('cu-quota-unit')).value = '1073741824';
     document.getElementById('cu-error').className = 'alert';
     document.getElementById('cu-error').textContent = '';
     showElement('create-user-modal', 'flex');
-    setTimeout(() => document.getElementById('cu-username').focus(), 100);
+    setTimeout(() => /** @type {HTMLInputElement} */ (document.getElementById('cu-username')).focus(), 100);
 }
 function closeCreateUserModal() {
     hideElement('create-user-modal');
 }
 
 async function submitCreateUser() {
-    const username = document.getElementById('cu-username').value.trim();
-    const password = document.getElementById('cu-password').value;
-    const email = document.getElementById('cu-email').value.trim() || null;
-    const role = document.getElementById('cu-role').value;
-    const quotaVal = parseFloat(document.getElementById('cu-quota-value').value) || 0;
-    const quotaUnit = parseInt(document.getElementById('cu-quota-unit').value, 10);
+    const username = /** @type {HTMLInputElement} */ (document.getElementById('cu-username')).value.trim();
+    const password = /** @type {HTMLInputElement} */ (document.getElementById('cu-password')).value;
+    const email = /** @type {HTMLInputElement} */ (document.getElementById('cu-email')).value.trim() || null;
+    const role = /** @type {HTMLInputElement} */ (document.getElementById('cu-role')).value;
+    const quotaVal = parseFloat(/** @type {HTMLInputElement} */ (document.getElementById('cu-quota-value')).value) || 0;
+    const quotaUnit = parseInt(/** @type {HTMLInputElement} */ (document.getElementById('cu-quota-unit')).value, 10);
     const quotaBytes = Math.round(quotaVal * quotaUnit);
 
     const errorEl = document.getElementById('cu-error');
@@ -486,7 +524,7 @@ async function submitCreateUser() {
         return;
     }
 
-    const btn = document.getElementById('cu-submit');
+    const btn = /** @type {HTMLButtonElement} */ (document.getElementById('cu-submit'));
     btn.disabled = true;
     btn.innerHTML = `<i class="fas fa-spinner fa-spin"></i> ${escapeHtml(i18n.t('admin.creating'))}`;
     try {
@@ -512,7 +550,7 @@ async function submitCreateUser() {
             errorEl.className = 'alert alert-error';
         }
     } catch (e) {
-        errorEl.textContent = i18n.t('admin.error_network', { message: e.message });
+        errorEl.textContent = i18n.t('admin.error_network', { message: /** @type {Error} */ (e).message });
         errorEl.className = 'alert alert-error';
     }
     btn.disabled = false;
@@ -520,21 +558,25 @@ async function submitCreateUser() {
 }
 
 let resetPwUserId = '';
+/**
+ * @param {string} userId
+ * @param {string} username
+ */
 function openResetPasswordModal(userId, username) {
     resetPwUserId = userId;
     document.getElementById('rp-username').textContent = username;
-    document.getElementById('rp-password').value = '';
+    /** @type {HTMLInputElement} */ (document.getElementById('rp-password')).value = '';
     document.getElementById('rp-error').className = 'alert';
     document.getElementById('rp-error').textContent = '';
     showElement('reset-pw-modal', 'flex');
-    setTimeout(() => document.getElementById('rp-password').focus(), 100);
+    setTimeout(() => /** @type {HTMLInputElement} */ (document.getElementById('rp-password')).focus(), 100);
 }
 function closeResetPasswordModal() {
     hideElement('reset-pw-modal');
 }
 
 async function submitResetPassword() {
-    const password = document.getElementById('rp-password').value;
+    const password = /** @type {HTMLInputElement} */ (document.getElementById('rp-password')).value;
     const errorEl = document.getElementById('rp-error');
     if (password.length < 8) {
         errorEl.textContent = i18n.t('admin.error_password_short');
@@ -542,7 +584,7 @@ async function submitResetPassword() {
         return;
     }
 
-    const btn = document.getElementById('rp-submit');
+    const btn = /** @type {HTMLButtonElement} */ (document.getElementById('rp-submit'));
     btn.disabled = true;
     btn.innerHTML = `<i class="fas fa-spinner fa-spin"></i> ${escapeHtml(i18n.t('admin.resetting'))}`;
     try {
@@ -560,13 +602,14 @@ async function submitResetPassword() {
             errorEl.className = 'alert alert-error';
         }
     } catch (e) {
-        errorEl.textContent = i18n.t('admin.error_network', { message: e.message });
+        errorEl.textContent = i18n.t('admin.error_network', { message: /** @type {Error} */ (e).message });
         errorEl.className = 'alert alert-error';
     }
     btn.disabled = false;
     btn.innerHTML = `<i class="fas fa-save"></i> ${escapeHtml(i18n.t('admin.reset_btn'))}`;
 }
 
+/** @param {boolean} enabled */
 async function toggleRegistration(enabled) {
     if (enabled) hideElement('registration-warning');
     else showElement('registration-warning', 'flex');
@@ -578,29 +621,33 @@ async function toggleRegistration(enabled) {
             body: JSON.stringify({ registration_enabled: enabled })
         });
         if (!resp.ok) {
-            document.getElementById('ds-registration').checked = !enabled;
+            /** @type {HTMLInputElement} */ (document.getElementById('ds-registration')).checked = !enabled;
             if (!enabled) showElement('registration-warning', 'flex');
             else hideElement('registration-warning');
             const e = await resp.json().catch(() => ({}));
             alert(e.message || i18n.t('admin.error_generic'));
         }
     } catch (e) {
-        document.getElementById('ds-registration').checked = !enabled;
+        /** @type {HTMLInputElement} */ (document.getElementById('ds-registration')).checked = !enabled;
         if (!enabled) showElement('registration-warning', 'flex');
         else hideElement('registration-warning');
-        alert(i18n.t('admin.error_network', { message: e.message }));
+        alert(i18n.t('admin.error_network', { message: /** @type {Error} */ (e).message }));
     }
 }
 
 document.getElementById('oidc-enabled').addEventListener('change', function () {
-    if (this.checked) showElement('oidc-form');
+    if (/** @type {HTMLInputElement} */ (this).checked) showElement('oidc-form');
     else hideElement('oidc-form');
 });
 document.getElementById('disable-password').addEventListener('change', function () {
-    if (this.checked) showElement('password-warning', 'flex');
+    if (/** @type {HTMLInputElement} */ (this).checked) showElement('password-warning', 'flex');
     else hideElement('password-warning');
 });
 
+/**
+ * @param {string} msg
+ * @param {string} type
+ */
 function showOidcStatus(msg, type) {
     const el = document.getElementById('oidc-status');
     el.textContent = msg;
@@ -613,12 +660,12 @@ function copyCallback() {
 }
 
 async function testConnection() {
-    const url = document.getElementById('issuer-url').value.trim();
+    const url = /** @type {HTMLInputElement} */ (document.getElementById('issuer-url')).value.trim();
     if (!url) {
         showOidcStatus('Enter an Issuer URL first', 'error');
         return;
     }
-    const btn = document.getElementById('discover-btn');
+    const btn = /** @type {HTMLButtonElement} */ (document.getElementById('discover-btn'));
     btn.disabled = true;
     btn.innerHTML = `<i class="fas fa-spinner fa-spin"></i> ${escapeHtml(i18n.t('admin.discovering'))}`;
     const resultDiv = document.getElementById('discovery-result');
@@ -639,32 +686,32 @@ async function testConnection() {
                 '</dd><dt>Auth Endpoint</dt><dd>' +
                 escapeHtml(r.authorization_endpoint || '—') +
                 '</dd></dl></div>';
-            if (!document.getElementById('provider-name').value && r.provider_name_suggestion)
-                document.getElementById('provider-name').value = r.provider_name_suggestion;
+            if (!(/** @type {HTMLInputElement} */ (document.getElementById('provider-name')).value) && r.provider_name_suggestion)
+                /** @type {HTMLInputElement} */ (document.getElementById('provider-name')).value = r.provider_name_suggestion;
         } else {
             resultDiv.innerHTML = `<div class="discovery-result fail"><strong><i class="fas fa-times-circle"></i> ${escapeHtml(r.message)}</strong></div>`;
         }
     } catch (e) {
-        resultDiv.innerHTML = `<div class="discovery-result fail"><i class="fas fa-times-circle"></i> Error: ${escapeHtml(e.message)}</div>`;
+        resultDiv.innerHTML = `<div class="discovery-result fail"><i class="fas fa-times-circle"></i> Error: ${escapeHtml(/** @type {Error} */ (e).message)}</div>`;
     }
     btn.disabled = false;
     btn.innerHTML = `<i class="fas fa-search"></i> ${escapeHtml(i18n.t('admin.auto_discover'))}`;
 }
 
 async function saveOidcSettings() {
-    const btn = document.getElementById('save-btn');
+    const btn = /** @type {HTMLButtonElement} */ (document.getElementById('save-btn'));
     btn.disabled = true;
     btn.innerHTML = `<i class="fas fa-spinner fa-spin"></i> ${escapeHtml(i18n.t('admin.saving'))}`;
     const body = {
-        enabled: document.getElementById('oidc-enabled').checked,
-        issuer_url: document.getElementById('issuer-url').value.trim(),
-        client_id: document.getElementById('client-id').value.trim(),
-        client_secret: document.getElementById('client-secret').value || null,
-        scopes: document.getElementById('scopes').value.trim() || null,
-        auto_provision: document.getElementById('auto-provision').checked,
-        admin_groups: document.getElementById('admin-groups').value.trim() || null,
-        disable_password_login: document.getElementById('disable-password').checked,
-        provider_name: document.getElementById('provider-name').value.trim() || null
+        enabled: /** @type {HTMLInputElement} */ (document.getElementById('oidc-enabled')).checked,
+        issuer_url: /** @type {HTMLInputElement} */ (document.getElementById('issuer-url')).value.trim(),
+        client_id: /** @type {HTMLInputElement} */ (document.getElementById('client-id')).value.trim(),
+        client_secret: /** @type {HTMLInputElement} */ (document.getElementById('client-secret')).value || null,
+        scopes: /** @type {HTMLInputElement} */ (document.getElementById('scopes')).value.trim() || null,
+        auto_provision: /** @type {HTMLInputElement} */ (document.getElementById('auto-provision')).checked,
+        admin_groups: /** @type {HTMLInputElement} */ (document.getElementById('admin-groups')).value.trim() || null,
+        disable_password_login: /** @type {HTMLInputElement} */ (document.getElementById('disable-password')).checked,
+        provider_name: /** @type {HTMLInputElement} */ (document.getElementById('provider-name')).value.trim() || null
     };
     try {
         const resp = await fetch(`${API}/admin/settings/oidc`, {
@@ -682,7 +729,7 @@ async function saveOidcSettings() {
             showOidcStatus(`Error: ${e.message || resp.statusText}`, 'error');
         }
     } catch (e) {
-        showOidcStatus(i18n.t('admin.error_network', { message: e.message }), 'error');
+        showOidcStatus(i18n.t('admin.error_network', { message: /** @type {Error} */ (e).message }), 'error');
     }
     btn.disabled = false;
     btn.innerHTML = `<i class="fas fa-save"></i> ${escapeHtml(i18n.t('admin.save_btn'))}`;
@@ -701,20 +748,25 @@ const STORAGE_PRESETS = {
     'wasabi':        { endpoint: 'https://s3.{region}.wasabisys.com',            region: 'us-east-1',   pathStyle: false },
 };
 
+/** @param {boolean} visible */
 function toggleS3Form(visible) {
     if (visible) showElement('storage-s3-form');
     else hideElement('storage-s3-form');
 }
 
 function onStoragePresetChange() {
-    const preset = document.getElementById('storage-preset').value;
-    const p = STORAGE_PRESETS[preset];
+    const preset = /** @type {HTMLInputElement} */ (document.getElementById('storage-preset')).value;
+    const p = STORAGE_PRESETS[/** @type {keyof typeof STORAGE_PRESETS} */ (preset)];
     if (!p) return;
-    if (p.endpoint) document.getElementById('storage-endpoint-url').value = p.endpoint;
-    if (p.region) document.getElementById('storage-region').value = p.region;
-    document.getElementById('storage-path-style').checked = p.pathStyle;
+    if (p.endpoint) /** @type {HTMLInputElement} */ (document.getElementById('storage-endpoint-url')).value = p.endpoint;
+    if (p.region) /** @type {HTMLInputElement} */ (document.getElementById('storage-region')).value = p.region;
+    /** @type {HTMLInputElement} */ (document.getElementById('storage-path-style')).checked = p.pathStyle;
 }
 
+/**
+ * @param {string} msg
+ * @param {string} type
+ */
 function showStorageStatus(msg, type) {
     const el = document.getElementById('storage-status');
     el.textContent = msg;
@@ -732,21 +784,23 @@ async function loadStorage() {
 
         // Backend selector
         document.querySelectorAll('input[name="storage-backend"]').forEach((r) => {
-            r.checked = r.value === s.backend;
+            const input = /** @type {HTMLInputElement} */ (r);
+            input.checked = input.value === s.backend;
         });
         toggleS3Form(s.backend === 's3');
 
         // S3 fields
-        document.getElementById('storage-endpoint-url').value = s.s3_endpoint_url || '';
-        document.getElementById('storage-bucket').value = s.s3_bucket || '';
-        document.getElementById('storage-region').value = s.s3_region || '';
-        document.getElementById('storage-access-key').value = '';
-        document.getElementById('storage-secret-key').value = '';
-        document.getElementById('storage-path-style').checked = s.s3_force_path_style;
+        /** @type {HTMLInputElement} */ (document.getElementById('storage-endpoint-url')).value = s.s3_endpoint_url || '';
+        /** @type {HTMLInputElement} */ (document.getElementById('storage-bucket')).value = s.s3_bucket || '';
+        /** @type {HTMLInputElement} */ (document.getElementById('storage-region')).value = s.s3_region || '';
+        /** @type {HTMLInputElement} */ (document.getElementById('storage-access-key')).value = '';
+        /** @type {HTMLInputElement} */ (document.getElementById('storage-secret-key')).value = '';
+        /** @type {HTMLInputElement} */ (document.getElementById('storage-path-style')).checked = s.s3_force_path_style;
 
         // Secret hints
         if (s.s3_access_key_set) {
-            document.getElementById('storage-access-key').placeholder = i18n.t('admin.storage_key_placeholder') || 'Leave empty to keep current value';
+            /** @type {HTMLInputElement} */ (document.getElementById('storage-access-key')).placeholder =
+                i18n.t('admin.storage_key_placeholder') || 'Leave empty to keep current value';
         }
         if (s.s3_secret_key_set) {
             showElement('storage-secret-hint');
@@ -755,7 +809,7 @@ async function loadStorage() {
         }
 
         // ENV badges
-        (s.env_overrides || []).forEach((field) => {
+        /** @type {string[]} */ (s.env_overrides || []).forEach((field) => {
             const badge = document.getElementById(`badge-${field}`);
             if (badge) badge.innerHTML = '<span class="badge badge-env">ENV</span>';
         });
@@ -766,7 +820,7 @@ async function loadStorage() {
         document.getElementById('storage-total-size').textContent = s.total_bytes_stored != null ? formatBytes(s.total_bytes_stored) : '—';
         document.getElementById('storage-dedup-ratio').textContent = s.dedup_ratio != null ? `${s.dedup_ratio.toFixed(2)}x` : '—';
     } catch (e) {
-        showStorageStatus(i18n.t('admin.error_network', { message: e.message }), 'error');
+        showStorageStatus(i18n.t('admin.error_network', { message: /** @type {Error} */ (e).message }), 'error');
     }
 
     // Also load migration status
@@ -774,19 +828,19 @@ async function loadStorage() {
 }
 
 async function saveStorageSettings() {
-    const btn = document.getElementById('btn-save-storage');
+    const btn = /** @type {HTMLButtonElement} */ (document.getElementById('btn-save-storage'));
     btn.disabled = true;
     btn.innerHTML = `<i class="fas fa-spinner fa-spin"></i> ${escapeHtml(i18n.t('admin.saving'))}`;
 
-    const backend = document.querySelector('input[name="storage-backend"]:checked').value;
+    const backend = /** @type {HTMLInputElement} */ (document.querySelector('input[name="storage-backend"]:checked')).value;
     const body = {
         backend,
-        s3_endpoint_url: document.getElementById('storage-endpoint-url').value.trim() || null,
-        s3_bucket: document.getElementById('storage-bucket').value.trim() || null,
-        s3_region: document.getElementById('storage-region').value.trim() || null,
-        s3_access_key: document.getElementById('storage-access-key').value || null,
-        s3_secret_key: document.getElementById('storage-secret-key').value || null,
-        s3_force_path_style: document.getElementById('storage-path-style').checked
+        s3_endpoint_url: /** @type {HTMLInputElement} */ (document.getElementById('storage-endpoint-url')).value.trim() || null,
+        s3_bucket: /** @type {HTMLInputElement} */ (document.getElementById('storage-bucket')).value.trim() || null,
+        s3_region: /** @type {HTMLInputElement} */ (document.getElementById('storage-region')).value.trim() || null,
+        s3_access_key: /** @type {HTMLInputElement} */ (document.getElementById('storage-access-key')).value || null,
+        s3_secret_key: /** @type {HTMLInputElement} */ (document.getElementById('storage-secret-key')).value || null,
+        s3_force_path_style: /** @type {HTMLInputElement} */ (document.getElementById('storage-path-style')).checked
     };
 
     try {
@@ -804,26 +858,26 @@ async function saveStorageSettings() {
             showStorageStatus(`Error: ${e.message || resp.statusText}`, 'error');
         }
     } catch (e) {
-        showStorageStatus(i18n.t('admin.error_network', { message: e.message }), 'error');
+        showStorageStatus(i18n.t('admin.error_network', { message: /** @type {Error} */ (e).message }), 'error');
     }
     btn.disabled = false;
     btn.innerHTML = `<i class="fas fa-save"></i> ${escapeHtml(i18n.t('admin.storage_save') || 'Save')}`;
 }
 
 async function testStorageConnection() {
-    const btn = document.getElementById('btn-test-storage');
+    const btn = /** @type {HTMLButtonElement} */ (document.getElementById('btn-test-storage'));
     btn.disabled = true;
     btn.innerHTML = `<i class="fas fa-spinner fa-spin"></i> ${escapeHtml(i18n.t('admin.testing') || 'Testing...')}`;
 
-    const backend = document.querySelector('input[name="storage-backend"]:checked').value;
+    const backend = /** @type {HTMLInputElement} */ (document.querySelector('input[name="storage-backend"]:checked')).value;
     const body = {
         backend,
-        s3_endpoint_url: document.getElementById('storage-endpoint-url').value.trim() || null,
-        s3_bucket: document.getElementById('storage-bucket').value.trim() || null,
-        s3_region: document.getElementById('storage-region').value.trim() || null,
-        s3_access_key: document.getElementById('storage-access-key').value || null,
-        s3_secret_key: document.getElementById('storage-secret-key').value || null,
-        s3_force_path_style: document.getElementById('storage-path-style').checked
+        s3_endpoint_url: /** @type {HTMLInputElement} */ (document.getElementById('storage-endpoint-url')).value.trim() || null,
+        s3_bucket: /** @type {HTMLInputElement} */ (document.getElementById('storage-bucket')).value.trim() || null,
+        s3_region: /** @type {HTMLInputElement} */ (document.getElementById('storage-region')).value.trim() || null,
+        s3_access_key: /** @type {HTMLInputElement} */ (document.getElementById('storage-access-key')).value || null,
+        s3_secret_key: /** @type {HTMLInputElement} */ (document.getElementById('storage-secret-key')).value || null,
+        s3_force_path_style: /** @type {HTMLInputElement} */ (document.getElementById('storage-path-style')).checked
     };
 
     try {
@@ -842,7 +896,7 @@ async function testStorageConnection() {
             showStorageStatus(`${i18n.t('admin.storage_test_failure') || 'Connection failed'}: ${escapeHtml(r.message)}`, 'error');
         }
     } catch (e) {
-        showStorageStatus(i18n.t('admin.error_network', { message: e.message }), 'error');
+        showStorageStatus(i18n.t('admin.error_network', { message: /** @type {Error} */ (e).message }), 'error');
     }
     btn.disabled = false;
     btn.innerHTML = `<i class="fas fa-vial"></i> ${escapeHtml(i18n.t('admin.storage_test_connection') || 'Test Connection')}`;
@@ -850,8 +904,13 @@ async function testStorageConnection() {
 
 /* ── Migration ── */
 
+/** @type {ReturnType<typeof setInterval> | null} */
 let migrationPollTimer = null;
 
+/**
+ * @param {string} msg
+ * @param {string} type
+ */
 function showMigrationMsg(msg, type) {
     const el = document.getElementById('migration-status-msg');
     el.textContent = msg;
@@ -859,6 +918,7 @@ function showMigrationMsg(msg, type) {
     el.style.display = '';
 }
 
+/** @param {any} m */
 function updateMigrationUI(m) {
     // Status badge
     const badge = document.getElementById('migration-status-badge');
@@ -937,7 +997,7 @@ async function loadMigrationStatus() {
 }
 
 async function startMigration() {
-    const btn = document.getElementById('btn-start-migration');
+    const btn = /** @type {HTMLButtonElement} */ (document.getElementById('btn-start-migration'));
     btn.disabled = true;
     try {
         const resp = await fetch(`${API}/admin/storage/migration/start`, {
@@ -954,7 +1014,7 @@ async function startMigration() {
             showMigrationMsg(`Error: ${e.message || resp.statusText}`, 'error');
         }
     } catch (e) {
-        showMigrationMsg(i18n.t('admin.error_network', { message: e.message }), 'error');
+        showMigrationMsg(i18n.t('admin.error_network', { message: /** @type {Error} */ (e).message }), 'error');
     }
     btn.disabled = false;
 }
@@ -992,7 +1052,7 @@ async function resumeMigration() {
 }
 
 async function verifyMigration() {
-    const btn = document.getElementById('btn-verify-migration');
+    const btn = /** @type {HTMLButtonElement} */ (document.getElementById('btn-verify-migration'));
     btn.disabled = true;
     btn.innerHTML = `<i class="fas fa-spinner fa-spin"></i> ${escapeHtml(i18n.t('admin.migration_verifying') || 'Verifying...')}`;
     const resultDiv = document.getElementById('migration-verify-result');
@@ -1015,7 +1075,7 @@ async function verifyMigration() {
         }
     } catch (e) {
         resultDiv.style.display = '';
-        resultDiv.innerHTML = `<div class="discovery-result fail"><i class="fas fa-times-circle"></i> Error: ${escapeHtml(e.message)}</div>`;
+        resultDiv.innerHTML = `<div class="discovery-result fail"><i class="fas fa-times-circle"></i> Error: ${escapeHtml(/** @type {Error} */ (e).message)}</div>`;
     }
     btn.disabled = false;
     btn.innerHTML = `<i class="fas fa-check-double"></i> ${escapeHtml(i18n.t('admin.migration_verify') || 'Verify Integrity')}`;
@@ -1036,7 +1096,7 @@ async function completeMigration() {
             showMigrationMsg(`Error: ${e.message || resp.statusText}`, 'error');
         }
     } catch (e) {
-        showMigrationMsg(i18n.t('admin.error_network', { message: e.message }), 'error');
+        showMigrationMsg(i18n.t('admin.error_network', { message: /** @type {Error} */ (e).message }), 'error');
     }
 }
 
@@ -1064,21 +1124,21 @@ async function init() {
         });
         if (oidcResp.ok) {
             const s = await oidcResp.json();
-            document.getElementById('oidc-enabled').checked = s.enabled;
+            /** @type {HTMLInputElement} */ (document.getElementById('oidc-enabled')).checked = s.enabled;
             if (s.enabled) showElement('oidc-form');
             else hideElement('oidc-form');
-            document.getElementById('provider-name').value = s.provider_name || '';
-            document.getElementById('issuer-url').value = s.issuer_url || '';
-            document.getElementById('client-id').value = s.client_id || '';
-            document.getElementById('scopes').value = s.scopes || 'openid profile email';
-            document.getElementById('auto-provision').checked = s.auto_provision;
-            document.getElementById('admin-groups').value = s.admin_groups || '';
-            document.getElementById('disable-password').checked = s.disable_password_login;
+            /** @type {HTMLInputElement} */ (document.getElementById('provider-name')).value = s.provider_name || '';
+            /** @type {HTMLInputElement} */ (document.getElementById('issuer-url')).value = s.issuer_url || '';
+            /** @type {HTMLInputElement} */ (document.getElementById('client-id')).value = s.client_id || '';
+            /** @type {HTMLInputElement} */ (document.getElementById('scopes')).value = s.scopes || 'openid profile email';
+            /** @type {HTMLInputElement} */ (document.getElementById('auto-provision')).checked = s.auto_provision;
+            /** @type {HTMLInputElement} */ (document.getElementById('admin-groups')).value = s.admin_groups || '';
+            /** @type {HTMLInputElement} */ (document.getElementById('disable-password')).checked = s.disable_password_login;
             if (s.disable_password_login) showElement('password-warning', 'flex');
             else hideElement('password-warning');
             document.getElementById('callback-url').textContent = s.callback_url;
             if (s.client_secret_set) showElement('secret-hint');
-            (s.env_overrides || []).forEach((field) => {
+            /** @type {string[]} */ (s.env_overrides || []).forEach((field) => {
                 const badge = document.getElementById(`badge-${field}`);
                 if (badge) badge.innerHTML = '<span class="badge badge-env">ENV</span>';
             });
@@ -1128,7 +1188,7 @@ document.getElementById('tab-btn-storage').addEventListener('click', function ()
 });
 
 document.getElementById('ds-registration').addEventListener('change', function () {
-    toggleRegistration(this.checked);
+    toggleRegistration(/** @type {HTMLInputElement} */ (this).checked);
 });
 
 document.getElementById('btn-create-user').addEventListener('click', openCreateUserModal);
@@ -1151,8 +1211,8 @@ document.getElementById('rp-submit').addEventListener('click', submitResetPasswo
 
 /* ── Storage event listeners ── */
 document.querySelectorAll('input[name="storage-backend"]').forEach((r) => {
-    r.addEventListener('change', function () {
-        toggleS3Form(this.value === 's3');
+    r.addEventListener('change', () => {
+        toggleS3Form(/** @type {HTMLInputElement} */ (r).value === 's3');
     });
 });
 document.getElementById('storage-preset').addEventListener('change', onStoragePresetChange);
diff --git a/static/js/views/device-verify/device-verify.js b/static/js/views/device-verify/device-verify.js
index 702c49c5..3a76b476 100644
--- a/static/js/views/device-verify/device-verify.js
+++ b/static/js/views/device-verify/device-verify.js
@@ -8,8 +8,10 @@ import { oxiIconsInit } from '../../core/icons.js';
     var deviceInfo = document.getElementById('device-info');
     var actionButtons = document.getElementById('action-buttons');
     var errorText = document.getElementById('error-text');
-    var btnApprove = document.getElementById('btn-approve');
-    var btnDeny = document.getElementById('btn-deny');
+    var btnApprove = /** @type {HTMLButtonElement} */ (document.getElementById('btn-approve'));
+    var btnDeny = /** @type {HTMLButtonElement} */ (document.getElementById('btn-deny'));
+
+    /** @type {ReturnType<typeof setTimeout>} */
     var debounceTimer = null;
     var currentCode = '';
 
@@ -24,12 +26,13 @@ import { oxiIconsInit } from '../../core/icons.js';
 
     // Auto-insert hyphen and lookup on input
     codeInput.addEventListener('input', (e) => {
-        var val = e.target.value.toUpperCase().replace(/[^A-Z0-9-]/g, '');
+        const target = /** @type {HTMLInputElement} */ (e.target);
+        var val = target.value.toUpperCase().replace(/[^A-Z0-9-]/g, '');
         // Auto-insert hyphen after 4 chars
         if (val.length === 4 && val.indexOf('-') === -1) {
             val = `${val}-`;
         }
-        e.target.value = val;
+        target.value = val;
         errorText.classList.add('hidden');
 
         // Debounce lookup
@@ -52,6 +55,11 @@ import { oxiIconsInit } from '../../core/icons.js';
         handleAction('deny');
     });
 
+    /**
+     *
+     * @param {string} code
+     * @returns
+     */
     async function lookupCode(code) {
         try {
             const resp = await fetch(`${API_BASE}/api/auth/device/verify?code=${encodeURIComponent(code)}`, {
@@ -81,6 +89,10 @@ import { oxiIconsInit } from '../../core/icons.js';
         }
     }
 
+    /**
+     *
+     * @param {'approve' | 'deny'} action
+     */
     async function handleAction(action) {
         btnApprove.disabled = true;
         btnDeny.disabled = true;
@@ -109,10 +121,14 @@ import { oxiIconsInit } from '../../core/icons.js';
         } catch (err) {
             btnApprove.disabled = false;
             btnDeny.disabled = false;
-            showError(err.message || 'Failed to process action.');
+            showError(/** @type {Error} */ (err).message || 'Failed to process action.');
         }
     }
 
+    /**
+     *
+     * @param {string} msg
+     */
     function showError(msg) {
         errorText.textContent = msg;
         errorText.classList.remove('hidden');
diff --git a/static/js/views/nextcloud/login.js b/static/js/views/nextcloud/login.js
index 86731ad5..52995c7f 100644
--- a/static/js/views/nextcloud/login.js
+++ b/static/js/views/nextcloud/login.js
@@ -6,7 +6,7 @@ if (!/^[0-9a-fA-F]+$/.test(token)) {
     document.body.innerHTML = '<p>Invalid session token.</p>';
     throw new Error('Invalid token format');
 }
-document.getElementById('login-flow-form').action = `/login/v2/flow/${token}`;
+/** @type {HTMLFormElement} */ (document.getElementById('login-flow-form')).action = `/login/v2/flow/${token}`;
 
 // Check if OIDC is available and configure SSO button
 (async () => {
diff --git a/static/js/views/profile/profile.js b/static/js/views/profile/profile.js
index fe78c307..9eedf929 100644
--- a/static/js/views/profile/profile.js
+++ b/static/js/views/profile/profile.js
@@ -4,10 +4,16 @@ import { oxiIconsInit } from '../../core/icons.js';
 
 const API = '/api';
 
+// TOOD: reuse common library
+/**
+ * @returns {Record<string, string>}
+ */
 function headers() {
     return { 'Content-Type': 'application/json', ...getCsrfHeaders() };
 }
 
+// TOOD: move to common library
+/** @param {number} bytes */
 function formatBytes(bytes) {
     if (bytes === 0) return '0 B';
     const k = 1024,
@@ -16,11 +22,13 @@ function formatBytes(bytes) {
     return `${parseFloat((bytes / k ** i).toFixed(1))} ${sizes[i]}`;
 }
 
+// TOOD: move to common library
+/** @param {string | null | undefined} dateStr */
 function timeAgo(dateStr) {
     if (!dateStr) return i18n.t('profile.never');
     const d = new Date(dateStr);
-    const now = new Date();
-    const secs = Math.floor((now - d) / 1000);
+    const now = Date.now();
+    const secs = Math.floor((now - d.valueOf()) / 1000);
     if (secs < 60) return i18n.t('profile.just_now');
     if (secs < 3600) return i18n.t('profile.minutes_ago', { n: Math.floor(secs / 60) });
     if (secs < 86400) return i18n.t('profile.hours_ago', { n: Math.floor(secs / 3600) });
@@ -104,11 +112,12 @@ function showError() {
     document.getElementById('auth-error').classList.remove('hidden');
 }
 
+/** @param {Event} e */
 async function changePassword(e) {
     e.preventDefault();
-    const currentPw = document.getElementById('current-password').value;
-    const newPw = document.getElementById('new-password').value;
-    const confirmPw = document.getElementById('confirm-password').value;
+    const currentPw = /** @type {HTMLInputElement} */ (document.getElementById('current-password')).value;
+    const newPw = /** @type {HTMLInputElement} */ (document.getElementById('new-password')).value;
+    const confirmPw = /** @type {HTMLInputElement} */ (document.getElementById('confirm-password')).value;
     const statusEl = document.getElementById('pw-status');
 
     if (newPw !== confirmPw) {
@@ -121,7 +130,7 @@ async function changePassword(e) {
         return false;
     }
 
-    const btn = document.getElementById('pw-submit');
+    const btn = /** @type {HTMLButtonElement} */ (document.getElementById('pw-submit'));
     btn.disabled = true;
     btn.innerHTML = `<i class="fas fa-spinner fa-spin"></i> ${escapeHtml(i18n.t('profile.updating'))}`;
 
@@ -138,7 +147,7 @@ async function changePassword(e) {
 
         if (resp.ok) {
             statusEl.innerHTML = `<div class="alert alert-success"><i class="fas fa-check-circle"></i> ${escapeHtml(i18n.t('profile.password_updated'))}</div>`;
-            document.getElementById('password-form').reset();
+            /** @type {HTMLFormElement} */ (document.getElementById('password-form')).reset();
         } else {
             const err = await resp.json().catch(() => ({}));
             statusEl.innerHTML =
@@ -149,7 +158,7 @@ async function changePassword(e) {
     } catch (err) {
         statusEl.innerHTML =
             '<div class="alert alert-error"><i class="fas fa-exclamation-circle"></i> ' +
-            escapeHtml(i18n.t('profile.error_network', { message: err.message })) +
+            escapeHtml(i18n.t('profile.error_network', { message: /** @type {Error} */ (err).message })) +
             '</div>';
     }
 
@@ -162,10 +171,12 @@ async function changePassword(e) {
 
 const AUTO_LABELS = ['Nextcloud', 'Nextcloud (OIDC)'];
 
+/** @param {{label: string, active?: boolean, id: string}} pw */
 function isAutoPassword(pw) {
     return AUTO_LABELS.includes(pw.label);
 }
 
+/** @param {{label: string, active?: boolean, id: string, created_at: string, last_used_at?: string}} pw */
 function renderPwRow(pw) {
     const tr = document.createElement('tr');
     const label = document.createElement('td');
@@ -210,7 +221,9 @@ async function loadAppPasswords() {
             return;
         }
         const data = await resp.json();
-        const passwords = data.app_passwords || data;
+        const passwords = /** @type {Array<{label: string, active?: boolean, id: string, created_at: string, last_used_at?: string}>} */ (
+            data.app_passwords || data
+        );
         const userPws = passwords.filter((pw) => {
             return !isAutoPassword(pw);
         });
@@ -236,7 +249,7 @@ async function loadAppPasswords() {
             autoSection.classList.add('hidden');
         } else {
             autoSection.classList.remove('hidden');
-            document.getElementById('app-pw-auto-count').textContent = autoPws.length;
+            document.getElementById('app-pw-auto-count').textContent = String(autoPws.length);
             const autoTbody = document.getElementById('app-pw-auto-tbody');
             autoTbody.innerHTML = '';
             for (const pw of autoPws) autoTbody.appendChild(renderPwRow(pw));
@@ -255,10 +268,10 @@ function toggleAutoPasswords() {
 }
 
 async function createAppPassword() {
-    const labelInput = document.getElementById('app-pw-label');
+    const labelInput = /** @type {HTMLInputElement} */ (document.getElementById('app-pw-label'));
     const label = labelInput.value.trim();
     const statusEl = document.getElementById('app-pw-status');
-    const btn = document.getElementById('app-pw-generate');
+    const btn = /** @type {HTMLButtonElement} */ (document.getElementById('app-pw-generate'));
 
     if (!label) {
         statusEl.innerHTML = `<div class="alert alert-error"><i class="fas fa-exclamation-circle"></i> ${escapeHtml(i18n.t('profile.error_label_required'))}</div>`;
@@ -291,7 +304,7 @@ async function createAppPassword() {
         labelInput.value = '';
         loadAppPasswords();
     } catch (err) {
-        statusEl.innerHTML = `<div class="alert alert-error"><i class="fas fa-exclamation-circle"></i> ${err.message}</div>`;
+        statusEl.innerHTML = `<div class="alert alert-error"><i class="fas fa-exclamation-circle"></i> ${/** @type {Error} */ (err).message}</div>`;
     } finally {
         btn.disabled = false;
         btn.innerHTML = `<i class="fas fa-plus"></i> ${escapeHtml(i18n.t('profile.generate'))}`;
@@ -309,6 +322,10 @@ function copyAppPassword() {
     });
 }
 
+/**
+ * @param {string} id
+ * @param {string} label
+ */
 async function revokeAppPassword(id, label) {
     if (!confirm(i18n.t('profile.confirm_revoke', { label: label }))) return;
     try {
@@ -325,10 +342,11 @@ async function revokeAppPassword(id, label) {
             alert(err.message || i18n.t('profile.error_revoke'));
         }
     } catch (err) {
-        alert(i18n.t('profile.error_network', { message: err.message }));
+        alert(i18n.t('profile.error_network', { message: /** @type {Error} */ (err).message }));
     }
 }
 
+/** @param {string} str */
 function escapeHtml(str) {
     var div = document.createElement('div');
     div.textContent = str || '';
diff --git a/static/js/views/public/publicShare.js b/static/js/views/public/publicShare.js
index 81462797..f569e81e 100644
--- a/static/js/views/public/publicShare.js
+++ b/static/js/views/public/publicShare.js
@@ -17,12 +17,12 @@ import { uiFileTypes } from '../../app/uiFileTypes.js';
     const $folder = document.getElementById('share-folder');
 
     const $pwForm = document.getElementById('password-form');
-    const $pwInput = document.getElementById('password-input');
+    const $pwInput = /** @type {HTMLInputElement} */ (document.getElementById('password-input'));
     const $pwError = document.getElementById('password-error');
 
     const $fileName = document.getElementById('file-name');
     const $fileMeta = document.getElementById('file-meta');
-    const $fileDl = document.getElementById('file-download');
+    const $fileDl = /** @type {HTMLAnchorElement} */ (document.getElementById('file-download'));
     const $expiredMsg = document.getElementById('expired-message');
 
     // ── Token from URL path (/s/{token}) ──────────────────────────
@@ -49,35 +49,49 @@ import { uiFileTypes } from '../../app/uiFileTypes.js';
     }
     let rootDisplayName = 'Shared folder';
 
+    /**
+     * @param {'loading'|'password'|'expired'|'file'|'folder'} name
+     */
     function showState(name) {
         for (const el of [$loading, $password, $expired, $file, $folder]) {
             if (el) el.classList.add('hidden');
         }
-        const target = {
+        /** @type {{ loading: HTMLElement|null, password: HTMLElement|null, expired: HTMLElement|null, file: HTMLElement|null, folder: HTMLElement|null }} */
+        const map = {
             loading: $loading,
             password: $password,
             expired: $expired,
             file: $file,
             folder: $folder
-        }[name];
+        };
+        const target = map[name];
         if (target) target.classList.remove('hidden');
         document.body.classList.toggle('gallery-mode', name === 'folder');
     }
 
     // ── Utilities ─────────────────────────────────────────────────
+    /**
+     * @param {string|null|undefined} s
+     * @returns {string}
+     */
     function escapeHtml(s) {
         return String(s == null ? '' : s).replace(
             /[&<>"']/g,
             (c) =>
+                /** @type {Record<string, string>} */
                 ({
                     '&': '&amp;',
                     '<': '&lt;',
                     '>': '&gt;',
                     '"': '&quot;',
                     "'": '&#39;'
-                })[c]
+                })[c] ?? c
         );
     }
+    /**
+     * @param {number} bytes
+     * @returns {string}
+     */
     function formatSize(bytes) {
         if (bytes == null || Number.isNaN(bytes)) return '';
         if (bytes < 1024) return `${bytes} B`;
@@ -90,6 +104,10 @@ import { uiFileTypes } from '../../app/uiFileTypes.js';
         }
         return `${v < 10 ? v.toFixed(1) : Math.round(v)} ${units[i]}`;
     }
+    /**
+     * @param {string|null|undefined} mime
+     * @returns {'image'|'video'|null}
+     */
     function mediaKind(mime) {
         const m = (mime || '').toLowerCase();
         if (m.startsWith('image/')) return 'image';
@@ -97,6 +115,9 @@ import { uiFileTypes } from '../../app/uiFileTypes.js';
         return null;
     }
     // ── Render share data ─────────────────────────────────────────
+    /**
+     * @param {any} data
+     */
     function renderShare(data) {
         if (data.item_type === 'folder') {
             rootDisplayName = data.item_name || 'Shared folder';
@@ -114,13 +135,15 @@ import { uiFileTypes } from '../../app/uiFileTypes.js';
             .then((res) => {
                 if (res.ok) return res.json();
                 if (res.status === 401) {
-                    return res.json().then((body) => {
-                        if (body?.requiresPassword) {
-                            showState('password');
-                            return null;
+                    return res.json().then(
+                        /** @type {(body:any) => null} */ (body) => {
+                            if (body?.requiresPassword) {
+                                showState('password');
+                                return null;
+                            }
+                            throw new Error('Unauthorized');
                         }
-                        throw new Error('Unauthorized');
-                    });
+                    );
                 }
                 if (res.status === 410) {
                     showState('expired');
@@ -171,7 +194,9 @@ import { uiFileTypes } from '../../app/uiFileTypes.js';
 
     // ── Folder gallery ────────────────────────────────────────────
 
+    /** @type {string | null} */
     let currentFolderId = null;
+    /** @type {string | null} */
     let currentFolderName = null;
 
     function initFolderGallery() {
@@ -195,17 +220,33 @@ import { uiFileTypes } from '../../app/uiFileTypes.js';
         return m ? m[1] : null;
     }
 
+    /**
+     * @param {string | null} folderId
+     * @returns {string}
+     */
     function listingUrl(folderId) {
         return folderId ? `/api/s/${TOKEN_ENC}/contents/${encodeURIComponent(folderId)}` : `/api/s/${TOKEN_ENC}/contents`;
     }
+    /**
+     * @param {string} fileId
+     * @returns {string}
+     */
     function fileUrl(fileId) {
         return `/api/s/${TOKEN_ENC}/file/${encodeURIComponent(fileId)}`;
     }
+    /**
+     * @param {string | null} folderId
+     * @returns {string}
+     */
     function zipUrl(folderId) {
         return folderId ? `/api/s/${TOKEN_ENC}/zip/${encodeURIComponent(folderId)}` : `/api/s/${TOKEN_ENC}/zip`;
     }
 
+    /** @type {AbortController | null} */
     let currentLoadController = null;
+    /**
+     * @param {string | null} folderId
+     */
     function loadAndRender(folderId) {
         if (currentLoadController) currentLoadController.abort();
         const controller = new AbortController();
@@ -236,6 +277,10 @@ import { uiFileTypes } from '../../app/uiFileTypes.js';
             });
     }
 
+    /**
+     * @param {any} listing
+     * @param {string | null} folderId
+     */
     function renderGallery(listing, folderId) {
         const isSubfolder = folderId !== null;
         const title = isSubfolder ? currentFolderName || 'Subfolder' : rootDisplayName;
@@ -252,7 +297,7 @@ import { uiFileTypes } from '../../app/uiFileTypes.js';
 
         const filesHtml =
             listing.files && listing.files.length > 0
-                ? `<h3 class="gallery-section-title">Files</h3><div class="gallery-files">${listing.files.map((f) => fileCardHtml(f)).join('')}</div>`
+                ? `<h3 class="gallery-section-title">Files</h3><div class="gallery-files">${listing.files.map((/** @type {any} */ f) => fileCardHtml(f)).join('')}</div>`
                 : '';
 
         const emptyHtml = empty ? '<div class="gallery-empty">This folder is empty.</div>' : '';
@@ -265,10 +310,18 @@ import { uiFileTypes } from '../../app/uiFileTypes.js';
         wireImageRetry();
     }
 
+    /**
+     * @param {any} folder
+     * @returns {string}
+     */
     function folderCardHtml(folder) {
         return `<a class="folder-card" href="#" data-action="open-folder" data-id="${escapeHtml(folder.id)}" data-name="${escapeHtml(folder.name)}"><i class="fas fa-folder folder-icon"></i><div class="card-body"><div class="card-name">${escapeHtml(folder.name)}</div><div class="card-meta">Subfolder</div></div></a>`;
     }
 
+    /**
+     * @param {any} file
+     * @returns {string}
+     */
     function fileCardHtml(file) {
         const url = fileUrl(file.id);
         const kind = mediaKind(file.mime_type);
@@ -286,7 +339,7 @@ import { uiFileTypes } from '../../app/uiFileTypes.js';
     }
 
     function wireGallery() {
-        for (const btn of $folder.querySelectorAll('.gallery-view-toggle button')) {
+        for (const btn of /** @type {NodeListOf<HTMLButtonElement>} */ ($folder.querySelectorAll('.gallery-view-toggle button'))) {
             btn.addEventListener('click', () => setViewMode(btn.dataset.view));
         }
         const backBtn = $folder.querySelector('[data-action="back"]');
@@ -296,14 +349,15 @@ import { uiFileTypes } from '../../app/uiFileTypes.js';
                 navigate(null, rootDisplayName);
             });
         }
-        for (const card of $folder.querySelectorAll('[data-action="open-folder"]')) {
+        for (const card of /** @type {NodeListOf<HTMLDivElement>} */ ($folder.querySelectorAll('[data-action="open-folder"]'))) {
             card.addEventListener('click', (e) => {
+                if (!(e instanceof MouseEvent)) return;
                 if (e.metaKey || e.ctrlKey || e.shiftKey || e.button !== 0) return;
                 e.preventDefault();
                 navigate(card.dataset.id, card.dataset.name);
             });
         }
-        const mediaCards = Array.from($folder.querySelectorAll('.file-card[data-mediakind]'));
+        const mediaCards = Array.from(/** @type {NodeListOf<HTMLDivElement>} */ ($folder.querySelectorAll('.file-card[data-mediakind]')));
         const items = mediaCards.map((el) => ({
             kind: el.dataset.mediakind,
             src: el.dataset.src,
@@ -318,6 +372,9 @@ import { uiFileTypes } from '../../app/uiFileTypes.js';
         });
     }
 
+    /**
+     * @param {string | null | undefined} v
+     */
     function setViewMode(v) {
         const mode = v === 'list' ? 'list' : 'grid';
         viewMode = mode;
@@ -327,11 +384,15 @@ import { uiFileTypes } from '../../app/uiFileTypes.js';
             // ignore
         }
         document.body.dataset.shareView = mode;
-        for (const b of $folder.querySelectorAll('.gallery-view-toggle button')) {
+        for (const b of /** @type {NodeListOf<HTMLButtonElement>} */ ($folder.querySelectorAll('.gallery-view-toggle button'))) {
             b.setAttribute('aria-pressed', String(b.dataset.view === mode));
         }
     }
 
+    /**
+     * @param {string | null} folderId
+     * @param {string | null | undefined} folderName
+     */
     function navigate(folderId, folderName) {
         currentFolderId = folderId;
         currentFolderName = folderName;
@@ -352,7 +413,7 @@ import { uiFileTypes } from '../../app/uiFileTypes.js';
     function wireLazyVideos() {
         const lazy = $folder.querySelectorAll('.file-thumb video[data-lazy-src]');
         if (!lazy.length) return;
-        const start = (v) => {
+        const start = (/** @type {HTMLVideoElement} */ v) => {
             v.addEventListener(
                 'loadedmetadata',
                 () => {
@@ -385,20 +446,21 @@ import { uiFileTypes } from '../../app/uiFileTypes.js';
                 (entries) => {
                     for (const e of entries) {
                         if (!e.isIntersecting) continue;
-                        if (e.target.dataset.lazySrc && !e.target.src) start(e.target);
-                        obs.unobserve(e.target);
+                        const target = /** @type {HTMLVideoElement} */ (e.target);
+                        if (target.dataset.lazySrc && !target.src) start(target);
+                        obs.unobserve(target);
                     }
                 },
                 { rootMargin: '300px' }
             );
             for (const v of lazy) obs.observe(v);
         } else {
-            for (const v of lazy) start(v);
+            for (const v of lazy) start(/** @type {HTMLVideoElement} */ (v));
         }
     }
 
     function wireImageRetry() {
-        for (const img of $folder.querySelectorAll('.file-thumb img')) {
+        for (const img of /** @type {NodeListOf<HTMLImageElement>} */ ($folder.querySelectorAll('.file-thumb img'))) {
             img.addEventListener('error', () => {
                 if (img.dataset.retried === '1') return;
                 img.dataset.retried = '1';
@@ -412,7 +474,12 @@ import { uiFileTypes } from '../../app/uiFileTypes.js';
     }
 
     // ── Lightbox ──────────────────────────────────────────────────
+    /**
+     * @typedef {{ root: HTMLElement, title: Element|null, download: HTMLAnchorElement|null, close: HTMLButtonElement|null, stage: Element|null, content: Element|null, prev: HTMLButtonElement|null, next: HTMLButtonElement|null }} LightboxRefs
+     */
+    /** @type {LightboxRefs | null} */
     let lb = null;
+    /** @type {Array<{kind: string|undefined, src: string|undefined, name: string|undefined}>} */
     let lbItems = [];
     let lbIndex = -1;
 
@@ -466,11 +533,18 @@ import { uiFileTypes } from '../../app/uiFileTypes.js';
         return lb;
     }
 
+    /**
+     * @param {Array<{kind: string|undefined, src: string|undefined, name: string|undefined}>} items
+     * @param {number} index
+     */
     function openLightbox(items, index) {
         ensureLightbox();
         lbItems = items;
         showLightboxItem(index);
     }
+    /**
+     * @param {number} i
+     */
     function showLightboxItem(i) {
         if (i < 0 || i >= lbItems.length) return;
         lbIndex = i;
@@ -497,6 +571,9 @@ import { uiFileTypes } from '../../app/uiFileTypes.js';
         lb.root.classList.remove('hidden');
         lb.root.setAttribute('aria-hidden', 'false');
     }
+    /**
+     * @param {number} delta
+     */
     function stepLightbox(delta) {
         const next = lbIndex + delta;
         if (next >= 0 && next < lbItems.length) showLightboxItem(next);
diff --git a/static/js/views/shared/sharedView.js b/static/js/views/shared/sharedView.js
index bd47ca88..4fe18e4e 100644
--- a/static/js/views/shared/sharedView.js
+++ b/static/js/views/shared/sharedView.js
@@ -6,18 +6,18 @@
 import { switchToFilesSection } from '../../app/navigation.js';
 import { ui } from '../../app/ui.js';
 import { getCsrfHeaders } from '../../core/csrf.js';
-import { formatDateShort } from '../../core/formatters.js';
+import { formatDateShort, isEmailValid } from '../../core/formatters.js';
 import { i18n } from '../../core/i18n.js';
 import { fileSharing } from '../../features/sharing/fileSharing.js';
 
-/** @import {Share} from '../../core/types.js' */
+/** @import {ShareItem} from '../../core/types.js' */
 
 const TTL = 5 * 60 * 1000; // 5 min
 
 const sharedView = {
     // State
 
-    /** @type {Array<Share>} */
+    /** @type {Array<ShareItem>} */
     items: [],
 
     _expires: 0,
@@ -25,8 +25,10 @@ const sharedView = {
     /** @type {Map<string, boolean>} key = "file:<id>" | "folder:<id>" */
     _knownItemsId: new Map(),
 
-    /** @type {Array<Share>} */
+    /** @type {Array<ShareItem>} */
     filteredItems: [],
+
+    /** @type {ShareItem | null} */
     currentItem: null,
 
     /** Auth header helper — tokens are in HttpOnly cookies now */
@@ -238,6 +240,7 @@ const sharedView = {
         // Close dropdowns when clicking outside
         document.addEventListener('click', (e) => {
             document.querySelectorAll('.shared-custom-select.open').forEach((sel) => {
+                if (!(e.target instanceof Node)) return;
                 if (!sel.contains(e.target)) sel.classList.remove('open');
             });
         });
@@ -249,8 +252,8 @@ const sharedView = {
             if (closeBtn) closeBtn.addEventListener('click', () => this.closeShareDialog());
             const copyLinkBtn = document.getElementById('sv-copy-link-btn');
             if (copyLinkBtn) copyLinkBtn.addEventListener('click', () => this.copyShareLink());
-            const enablePw = document.getElementById('sv-enable-password');
-            const pwField = document.getElementById('sv-share-password');
+            const enablePw = /** @type {HTMLInputElement} */ (document.getElementById('sv-enable-password'));
+            const pwField = /** @type {HTMLInputElement} */ (document.getElementById('sv-share-password'));
             if (enablePw)
                 enablePw.addEventListener('change', () => {
                     if (pwField) {
@@ -260,8 +263,8 @@ const sharedView = {
                 });
             const genPwBtn = document.getElementById('sv-generate-password');
             if (genPwBtn) genPwBtn.addEventListener('click', () => this.generatePassword());
-            const enableExp = document.getElementById('sv-enable-expiration');
-            const expField = document.getElementById('sv-share-expiration');
+            const enableExp = /** @type {HTMLInputElement} */ (document.getElementById('sv-enable-expiration'));
+            const expField = /** @type {HTMLInputElement} */ (document.getElementById('sv-share-expiration'));
             if (enableExp)
                 enableExp.addEventListener('change', () => {
                     if (expField) {
@@ -294,6 +297,13 @@ const sharedView = {
     },
 
     // Initialize a custom select dropdown
+    /**
+     *
+     * @param {string} wrapperId
+     * @param {string} toggleId
+     * @param {string} dropdownId
+     * @returns
+     */
     _initCustomSelect(wrapperId, toggleId, dropdownId) {
         const wrapper = document.getElementById(wrapperId);
         const toggle = document.getElementById(toggleId);
@@ -330,14 +340,14 @@ const sharedView = {
 
     // Filter and sort items
     filterAndSortItems() {
-        const filterTypeActive = document.querySelector('#filter-type-dropdown .shared-select-option.active');
-        const sortByActive = document.querySelector('#sort-by-dropdown .shared-select-option.active');
+        const filterTypeActive = /** @type {HTMLDivElement} */ (document.querySelector('#filter-type-dropdown .shared-select-option.active'));
+        const sortByActive = /** @type {HTMLDivElement} */ (document.querySelector('#sort-by-dropdown .shared-select-option.active'));
 
         const type = filterTypeActive ? filterTypeActive.dataset.value : 'all';
         const sort = sortByActive ? sortByActive.dataset.value : 'date';
 
         // Use the main top-bar search input
-        const searchInput = document.getElementById('search-input');
+        const searchInput = /** @type {HTMLInputElement} */ (document.getElementById('search-input'));
         const searchTerm = searchInput ? searchInput.value.toLowerCase() : '';
 
         this.filteredItems = this.items.filter((item) => {
@@ -396,23 +406,23 @@ const sharedView = {
             nameCell.appendChild(nameSpan);
 
             const typeCell = document.createElement('td');
-            typeCell.textContent = item.item_type === 'file' ? this.translate('shared_typeFile', 'File') : this.translate('shared_typeFolder', 'Folder');
+            typeCell.textContent = item.item_type === 'file' ? i18n.t('shared_typeFile', 'File') : i18n.t('shared_typeFolder', 'Folder');
 
             const dateCell = document.createElement('td');
-            dateCell.textContent = this.formatDate(item.created_at);
+            dateCell.textContent = formatDateShort(item.created_at);
 
             const expCell = document.createElement('td');
-            expCell.textContent = item.expires_at ? this.formatDate(item.expires_at) : this.translate('shared_noExpiration', 'No expiration');
+            expCell.textContent = item.expires_at ? formatDateShort(item.expires_at) : i18n.t('shared_noExpiration', 'No expiration');
 
             const permCell = document.createElement('td');
             const perms = [];
-            if (item.permissions?.read) perms.push(this.translate('share_permissionRead', 'Read'));
-            if (item.permissions?.write) perms.push(this.translate('share_permissionWrite', 'Write'));
-            if (item.permissions?.reshare) perms.push(this.translate('share_permissionReshare', 'Reshare'));
+            if (item.permissions?.read) perms.push(i18n.t('share_permissionRead', 'Read'));
+            if (item.permissions?.write) perms.push(i18n.t('share_permissionWrite', 'Write'));
+            if (item.permissions?.reshare) perms.push(i18n.t('share_permissionReshare', 'Reshare'));
             permCell.textContent = perms.join(', ') || 'Read';
 
             const pwCell = document.createElement('td');
-            pwCell.textContent = item.has_password ? this.translate('shared_hasPassword', 'Yes') : this.translate('shared_noPassword', 'No');
+            pwCell.textContent = item.has_password ? i18n.t('shared_hasPassword', 'Yes') : i18n.t('shared_noPassword', 'No');
 
             const actionsCell = document.createElement('td');
             actionsCell.className = 'shared-item-actions';
@@ -420,30 +430,30 @@ const sharedView = {
             const editBtn = document.createElement('button');
             editBtn.className = 'action-btn edit-btn';
             editBtn.innerHTML = '<span class="action-icon">✏️</span>';
-            editBtn.title = this.translate('shared_editShare', 'Edit Share');
+            editBtn.title = i18n.t('shared_editShare', 'Edit Share');
             editBtn.addEventListener('click', () => this.openShareDialog(item));
 
             const notifyBtn = document.createElement('button');
             notifyBtn.className = 'action-btn notify-btn';
             notifyBtn.innerHTML = '<span class="action-icon">📧</span>';
-            notifyBtn.title = this.translate('shared_notifyShare', 'Notify Someone');
+            notifyBtn.title = i18n.t('shared_notifyShare', 'Notify Someone');
             notifyBtn.addEventListener('click', () => this.openNotificationDialog(item));
 
             const copyBtn = document.createElement('button');
             copyBtn.className = 'action-btn copy-btn';
             copyBtn.innerHTML = '<span class="action-icon">📋</span>';
-            copyBtn.title = this.translate('shared_copyLink', 'Copy Link');
+            copyBtn.title = i18n.t('shared_copyLink', 'Copy Link');
             copyBtn.addEventListener('click', () => {
                 navigator.clipboard
                     .writeText(item.url)
-                    .then(() => this.showNotification(this.translate('shared_linkCopied', 'Link copied!')))
-                    .catch(() => this.showNotification(this.translate('shared_linkCopyFailed', 'Failed to copy link'), 'error'));
+                    .then(() => ui.showNotification(i18n.t('shared_linkCopied', 'Link copied!'), 'success'))
+                    .catch(() => ui.showNotification(i18n.t('shared_linkCopyFailed', 'Failed to copy link'), 'error'));
             });
 
             const rmBtn = document.createElement('button');
             rmBtn.className = 'action-btn remove-btn';
             rmBtn.innerHTML = '<span class="action-icon">🗑️</span>';
-            rmBtn.title = this.translate('shared_removeShare', 'Remove Share');
+            rmBtn.title = i18n.t('shared_removeShare', 'Remove Share');
             rmBtn.addEventListener('click', () => {
                 this.currentItem = item;
                 this.removeSharedItem();
@@ -456,6 +466,11 @@ const sharedView = {
     },
 
     // Open share dialog
+    /**
+     *
+     * @param {ShareItem} item
+     * @returns {void}
+     */
     openShareDialog(item) {
         this.currentItem = item;
         const shareDialog = document.getElementById('shared-view-edit-dialog');
@@ -463,14 +478,14 @@ const sharedView = {
 
         const iconEl = document.getElementById('sv-dialog-icon');
         const nameEl = document.getElementById('sv-dialog-name');
-        const urlEl = document.getElementById('sv-share-link-url');
-        const enablePw = document.getElementById('sv-enable-password');
-        const pwField = document.getElementById('sv-share-password');
-        const enableExp = document.getElementById('sv-enable-expiration');
-        const expField = document.getElementById('sv-share-expiration');
-        const permRead = document.getElementById('sv-permission-read');
-        const permWrite = document.getElementById('sv-permission-write');
-        const permReshare = document.getElementById('sv-permission-reshare');
+        const urlEl = /** @type {HTMLInputElement} */ (document.getElementById('sv-share-link-url'));
+        const enablePw = /** @type {HTMLInputElement} */ (document.getElementById('sv-enable-password'));
+        const pwField = /** @type {HTMLInputElement} */ (document.getElementById('sv-share-password'));
+        const enableExp = /** @type {HTMLInputElement} */ (document.getElementById('sv-enable-expiration'));
+        const expField = /** @type {HTMLInputElement} */ (document.getElementById('sv-share-expiration'));
+        const permRead = /** @type {HTMLInputElement} */ (document.getElementById('sv-permission-read'));
+        const permWrite = /** @type {HTMLInputElement} */ (document.getElementById('sv-permission-write'));
+        const permReshare = /** @type {HTMLInputElement} */ (document.getElementById('sv-permission-reshare'));
 
         if (!shareDialog) return;
         if (iconEl) iconEl.textContent = item.item_type === 'file' ? '📄' : '📁';
@@ -505,14 +520,19 @@ const sharedView = {
         this.currentItem = null;
     },
 
+    /**
+     *
+     * @param {ShareItem} item
+     * @returns {void}
+     */
     openNotificationDialog(item) {
         this.currentItem = item;
         const dn = item.item_name || item.item_id || 'Unknown';
         const d = document.getElementById('sv-notification-dialog');
         const iconEl = document.getElementById('sv-notify-dialog-icon');
         const nameEl = document.getElementById('sv-notify-dialog-name');
-        const emailEl = document.getElementById('sv-notification-email');
-        const msgEl = document.getElementById('sv-notification-message');
+        const emailEl = /** @type {HTMLInputElement} */ (document.getElementById('sv-notification-email'));
+        const msgEl = /** @type {HTMLInputElement} */ (document.getElementById('sv-notification-message'));
 
         if (!d) return;
         if (iconEl) iconEl.textContent = item.item_type === 'file' ? '📄' : '📁';
@@ -529,18 +549,18 @@ const sharedView = {
     },
 
     copyShareLink() {
-        const el = document.getElementById('sv-share-link-url');
+        const el = /** @type {HTMLInputElement} */ (document.getElementById('sv-share-link-url'));
         if (!el) return;
         navigator.clipboard
             .writeText(el.value)
-            .then(() => this.showNotification(this.translate('shared_linkCopied', 'Link copied!')))
-            .catch(() => this.showNotification(this.translate('shared_linkCopyFailed', 'Failed to copy link'), 'error'));
+            .then(() => ui.showNotification(i18n.t('shared_linkCopied', 'Link copied!'), 'success'))
+            .catch(() => ui.showNotification(i18n.t('shared_linkCopyFailed', 'Failed to copy link'), 'error'));
     },
 
     // Generate secure password with crypto API
     generatePassword() {
-        const pwField = document.getElementById('sv-share-password');
-        const enablePw = document.getElementById('sv-enable-password');
+        const pwField = /** @type {HTMLInputElement} */ (document.getElementById('sv-share-password'));
+        const enablePw = /** @type {HTMLInputElement} */ (document.getElementById('sv-enable-password'));
         if (!pwField || !enablePw) return;
 
         const chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789!@#$%^&*';
@@ -559,13 +579,13 @@ const sharedView = {
     async updateSharedItem() {
         if (!this.currentItem) return;
 
-        const permRead = document.getElementById('sv-permission-read');
-        const permWrite = document.getElementById('sv-permission-write');
-        const permReshare = document.getElementById('sv-permission-reshare');
-        const enablePw = document.getElementById('sv-enable-password');
-        const pwField = document.getElementById('sv-share-password');
-        const enableExp = document.getElementById('sv-enable-expiration');
-        const expField = document.getElementById('sv-share-expiration');
+        const permRead = /** @type {HTMLInputElement} */ (document.getElementById('sv-permission-read'));
+        const permWrite = /** @type {HTMLInputElement} */ (document.getElementById('sv-permission-write'));
+        const permReshare = /** @type {HTMLInputElement} */ (document.getElementById('sv-permission-reshare'));
+        const enablePw = /** @type {HTMLInputElement} */ (document.getElementById('sv-enable-password'));
+        const pwField = /** @type {HTMLInputElement} */ (document.getElementById('sv-share-password'));
+        const enableExp = /** @type {HTMLInputElement} */ (document.getElementById('sv-enable-expiration'));
+        const expField = /** @type {HTMLInputElement} */ (document.getElementById('sv-share-expiration'));
 
         const body = {
             permissions: {
@@ -588,10 +608,10 @@ const sharedView = {
                 const err = await res.json().catch(() => ({}));
                 throw new Error(err.error || `Server error ${res.status}`);
             }
-            this.showNotification(this.translate('shared_itemUpdated', 'Share settings updated'));
+            ui.showNotification(i18n.t('shared_itemUpdated', 'Share settings updated'), 'success');
         } catch (err) {
             console.error('Error updating share:', err);
-            this.showNotification(err.message || 'Error updating share', 'error');
+            ui.showNotification(/** @type {Error} */ (err).message || 'Error updating share', 'error');
         }
         // update UI
         ui.setSharedVisualState(this.currentItem.item_id, this.currentItem.item_type, true);
@@ -611,10 +631,10 @@ const sharedView = {
                 headers: this._headers()
             });
             if (!res.ok && res.status !== 204) throw new Error(`Server error ${res.status}`);
-            this.showNotification(this.translate('shared_itemRemoved', 'Share removed'));
+            ui.showNotification(i18n.t('shared_itemRemoved', 'Share removed'), 'success');
         } catch (err) {
             console.error('Error removing share:', err);
-            this.showNotification('Error removing share', 'error');
+            ui.showNotification('Error removing share', 'error');
         }
 
         this.closeShareDialog();
@@ -627,13 +647,13 @@ const sharedView = {
     // Send notification (stub)
     sendNotification() {
         if (!this.currentItem) return;
-        const emailEl = document.getElementById('sv-notification-email');
-        const msgEl = document.getElementById('sv-notification-message');
+        const emailEl = /** @type {HTMLInputElement} */ (document.getElementById('sv-notification-email'));
+        const msgEl = /** @type {HTMLInputElement} */ (document.getElementById('sv-notification-message'));
         const email = emailEl ? emailEl.value.trim() : '';
         const message = msgEl ? msgEl.value.trim() : '';
 
-        if (!email || !this.validateEmail(email)) {
-            this.showNotification(this.translate('shared_invalidEmail', 'Please enter a valid email address'), 'error');
+        if (!email || !isEmailValid(email)) {
+            ui.showNotification(i18n.t('shared_invalidEmail', 'Please enter a valid email address'), 'error');
             return;
         }
 
@@ -642,30 +662,10 @@ const sharedView = {
                 .sendShareNotification(this.currentItem.url, email, message)
                 .then(() => {
                     this.closeNotificationDialog();
-                    this.showNotification(this.translate('shared_notificationSent', 'Notification sent'));
+                    ui.showNotification(i18n.t('shared_notificationSent', 'Notification sent'), 'success');
                 })
-                .catch(() => this.showNotification(this.translate('shared_notificationFailed', 'Failed to send notification'), 'error'));
+                .catch(() => ui.showNotification(i18n.t('shared_notificationFailed', 'Failed to send notification'), 'error'));
         }
-    },
-
-    showNotification(message, type = 'success') {
-        if (ui?.showNotification) {
-            ui.showNotification(message, type);
-        } else {
-            alert(message);
-        }
-    },
-
-    validateEmail(email) {
-        return /^[^\s@]+@[^\s@]+\.[^\s@]+$/.test(email);
-    },
-
-    formatDate(value) {
-        return formatDateShort(value);
-    },
-
-    translate(key, defaultText) {
-        return i18n.t(key, defaultText);
     }
 };