Implement admin database stats dashboard

Add admin-only database statistics dashboard
- Introduces types for database statistics and recent additions
- Implements hooks to fetch statistics and recent additions via RPCs
- Adds UI components for stats cards and a recent additions table
- Integrates new AdminDatabaseStats page and routing under /admin/database-stats
- Updates admin sidebar and app routes to expose the new dashboard
- Enables real-time updates and export capabilities for recent additions

src/App.tsx

@@ -69,6 +69,7 @@ const AdminSystemLog = lazy(() => import("./pages/AdminSystemLog"));
 const AdminUsers = lazy(() => import("./pages/AdminUsers"));
 const AdminBlog = lazy(() => import("./pages/AdminBlog"));
 const AdminSettings = lazy(() => import("./pages/AdminSettings"));
+const AdminDatabaseStats = lazy(() => import("./pages/AdminDatabaseStats"));
 const AdminContact = lazy(() => import("./pages/admin/AdminContact"));
 const AdminEmailSettings = lazy(() => import("./pages/admin/AdminEmailSettings"));
 const ErrorMonitoring = lazy(() => import("./pages/admin/ErrorMonitoring"));
@@ -414,6 +415,14 @@ function AppContent(): React.JSX.Element {
                       </AdminErrorBoundary>
                     } 
                   />
+                  <Route 
+                    path="/admin/database-stats" 
+                    element={
+                      <AdminErrorBoundary section="Database Statistics">
+                        <AdminDatabaseStats />
+                      </AdminErrorBoundary>
+                    } 
+                  />
                   
                   {/* Utility routes - lazy loaded */}
                   <Route path="/force-logout" element={<ForceLogout />} />