feat(ui): handle errors on folder creation or folder/file renaming

- protect file_management_service::rename_file with validate_storage_name
 - remove specific rename modal and use the generic modal class (less duplicate)
 - handle errors on modal action: do not close the modal on error and display this error
 - hide "Go to parent folder" contextMenu if section is files and folder is the same as current one

static/js/app/main.js

@@ -203,10 +203,9 @@ function setupActionsBarDelegation() {
                 break;
             }
             case 'new-folder-btn': {
-                const folderName = await Modal.promptNewFolder();
-                if (folderName) {
-                    fileOps.createFolder(folderName);
-                }
+                await Modal.promptNewFolder(async (name) => {
+                    await fileOps.createFolder(name);
+                });
                 break;
             }
             case 'grid-view-btn':

static/js/app/ui.js

@@ -112,29 +112,6 @@ const ui = {
             i18n.translateElement(fileMenu);
         }
 
-        // Rename dialog — modern
-        if (!document.getElementById('rename-dialog')) {
-            const renameDialog = document.createElement('div');
-            renameDialog.classList.add('rename-dialog', 'hidden');
-            renameDialog.id = 'rename-dialog';
-            renameDialog.innerHTML = `
-                <div class="rename-dialog-content">
-                    <div class="rename-dialog-header">
-                        <i class="fas fa-pen dialog-header-icon"></i>
-                        <span data-i18n="dialogs.rename_folder">Rename</span>
-                    </div>
-                    <div class="rename-dialog-body">
-                        <input type="text" id="rename-input" data-i18n-placeholder="dialogs.new_name" placeholder="New name">
-                    </div>
-                    <div class="rename-dialog-buttons">
-                        <button class="btn btn-secondary" id="rename-cancel-btn" data-i18n="actions.cancel">Cancel</button>
-                        <button class="btn btn-primary" id="rename-confirm-btn" data-i18n="actions.rename">Rename</button>
-                    </div>
-                </div>
-            `;
-            document.body.appendChild(renameDialog);
-        }
-
         // Move dialog — modern with navigation
         if (!document.getElementById('move-file-dialog')) {
             const moveDialog = document.createElement('div');