Remove icon from Sources page title bar

Consistent with other pages that don't show icons in the title section.

🤖 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

@@ -20,7 +20,6 @@ export default function Sources() {
                         <span className="material-symbols-outlined">menu</span>
                     </button>
                     <div className="admin-title-section">
-                        <span className="material-symbols-outlined">database</span>
                         <span className="admin-title-text">{t.sourcesPage.title}</span>
                     </div>
                 </div>