Add swipe-to-open sidebar on all pages + fix bottom bar styling

- Create SwipeableContent component for sidebar swipe on non-tab pages
- Add swipe-to-close sidebar from overlay
- Make swipe work from entire page (ignoring interactive elements)
- Show title and divider on desktop when tab bar is at bottom
- Hide title/divider only on mobile for bottom position

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/src/pages/admin/Sources.tsx

@@ -2,6 +2,7 @@ import { useAuth } from '../../contexts/AuthContext';
 import { useTranslation } from '../../contexts/LanguageContext';
 import { useSidebar } from '../../contexts/SidebarContext';
 import TabsScroller from '../../components/TabsScroller';
+import { SwipeableContent } from '../../components/SwipeableContent';
 import '../../styles/AdminPanel.css';
 
 export default function Sources() {
@@ -14,7 +15,7 @@ export default function Sources() {
     }
 
     return (
-        <main className="main-content admin-panel-root">
+        <SwipeableContent className="main-content admin-panel-root">
             <div className="admin-tabs-container">
                 <TabsScroller className="admin-tabs-slider">
                     <button className="mobile-menu-btn" onClick={toggleMobileMenu} aria-label={t.theme.toggleMenu}>
@@ -35,6 +36,6 @@ export default function Sources() {
                     <p>{t.sourcesPage.comingSoon}</p>
                 </div>
             </div>
-        </main>
+        </SwipeableContent>
     );
 }