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/integrations/supabase/types.ts

@@ -6829,6 +6829,7 @@ export type Database = {
       generate_ticket_number: { Args: never; Returns: string }
       get_auth0_sub_from_jwt: { Args: never; Returns: string }
       get_current_user_id: { Args: never; Returns: string }
+      get_database_statistics: { Args: never; Returns: Json }
       get_email_change_status: { Args: never; Returns: Json }
       get_filtered_profile: {
         Args: { _profile_user_id: string; _viewer_id?: string }
@@ -6853,6 +6854,21 @@ export type Database = {
           id: string
         }[]
       }
+      get_recent_additions: {
+        Args: { limit_count?: number }
+        Returns: {
+          created_at: string
+          created_by_avatar: string
+          created_by_id: string
+          created_by_username: string
+          entity_id: string
+          entity_name: string
+          entity_slug: string
+          entity_type: string
+          image_url: string
+          park_slug: string
+        }[]
+      }
       get_recent_changes: {
         Args: { limit_count?: number }
         Returns: {