Frontend optimizations: SVG icons, remove updateFileIcons, unify rendering, scope translatePage

- Replace Font Awesome CDN with inline SVG system (icons.js + MutationObserver)
- Remove updateFileIcons() (~140 lines) - redundant with backend icon_class + MutationObserver
- Migrate favorites.js and recent.js to use shared ui.renderFolders/renderFiles (eliminate ~260 lines of duplicate rendering + per-item event listeners)
- Add view-mode aware click delegation for favorites/recent views
- Fix _createFileCard to apply icon_special_class
- Add translateElement(root) for scoped i18n translation
- Replace full-page translatePage() calls with scoped translateElement() or inline t()
- Remove redundant translatePage() calls in shared.js and auth.js
- Remove Alpine.js from Service Worker cache

static/js/contextMenus.js

@@ -92,8 +92,6 @@ const contextMenus = {
                             // Open with inline viewer
                             if (window.inlineViewer) {
                                 window.inlineViewer.openFile(fileDetails);
-                            } else if (window.fileViewer) {
-                                window.fileViewer.open(fileDetails);
                             } else {
                                 // If no viewer is available, download directly
                                 window.fileOps.downloadFile(file.id, file.name);
@@ -468,9 +466,9 @@ const contextMenus = {
                     window.app.selectedTargetFolderId = "";
                 });
 
-                // Translate new elements
-                if (window.i18n && window.i18n.translatePage) {
-                    window.i18n.translatePage();
+                // Translate new elements (scoped to container)
+                if (window.i18n && window.i18n.translateElement) {
+                    window.i18n.translateElement(folderSelectContainer);
                 }
             }
         } catch (error) {