feat(frontend): i18n expansion, admin/profile i18n, grid/list view fix, empty state

- Add 5 new locales (hi, ar, ru, ja, ko) — now 14 total
- Admin panel: 117 i18n keys, confirm modal, animated tabs, no inline handlers
- Profile page: 58 i18n keys with data-i18n attributes
- Fix i18n safeT() shadowing bug and translationsLoaded timing
- Fix grid/list view: list header no longer shows in grid mode on login
- Fix classList.toggle hidden sync for view switching across all nav functions
- Revert .hidden important that broke login page rendering
- Add files empty state (no_files + empty_hint) with translations
- Fix language selector dropdown scroll and styling
- Fix admin panel scroll with sticky tabs

static/js/app/filesView.js

@@ -110,8 +110,19 @@ async function loadFiles(options = {}) {
         const folderList = Array.isArray(listing.folders) ? listing.folders : [];
         const fileList = Array.isArray(listing.files) ? listing.files : [];
 
-        window.ui.renderFolders(folderList);
-        window.ui.renderFiles(fileList);
+        if (folderList.length === 0 && fileList.length === 0) {
+            const emptyState = document.createElement('div');
+            emptyState.className = 'empty-state';
+            emptyState.innerHTML = `
+                <i class="fas fa-folder-open empty-state-icon"></i>
+                <p>${_t('files.no_files')}</p>
+                <p>${_t('files.empty_hint')}</p>
+            `;
+            elements.filesGrid.appendChild(emptyState);
+        } else {
+            window.ui.renderFolders(folderList);
+            window.ui.renderFiles(fileList);
+        }
 
         console.log(`Loaded ${folderList.length} folders and ${fileList.length} files`);
     } catch (error) {