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/hooks/useAdminDatabaseStats.ts

@@ -0,0 +1,21 @@
+import { useQuery } from '@tanstack/react-query';
+import { supabase } from '@/integrations/supabase/client';
+import { queryKeys } from '@/lib/queryKeys';
+import type { DatabaseStatistics } from '@/types/database-stats';
+
+export function useAdminDatabaseStats() {
+  return useQuery({
+    queryKey: queryKeys.admin.databaseStats(),
+    queryFn: async () => {
+      const { data, error } = await supabase.rpc('get_database_statistics');
+
+      if (error) {
+        throw error;
+      }
+
+      return data as unknown as DatabaseStatistics;
+    },
+    staleTime: 5 * 60 * 1000, // 5 minutes
+    refetchInterval: 60 * 1000, // Auto-refetch every 60 seconds
+  });
+}

src/hooks/useRecentAdditions.ts

@@ -0,0 +1,74 @@
+import { useQuery } from '@tanstack/react-query';
+import { supabase } from '@/integrations/supabase/client';
+import { queryKeys } from '@/lib/queryKeys';
+import type { RecentAddition } from '@/types/database-stats';
+import { useEffect } from 'react';
+
+export function useRecentAdditions(limit: number = 50, entityTypeFilter?: string) {
+  const query = useQuery({
+    queryKey: queryKeys.admin.recentAdditions(limit),
+    queryFn: async () => {
+      const { data, error } = await supabase.rpc('get_recent_additions', {
+        limit_count: limit
+      });
+
+      if (error) {
+        throw error;
+      }
+
+      return data as unknown as RecentAddition[];
+    },
+    staleTime: 2 * 60 * 1000, // 2 minutes
+    refetchInterval: 30 * 1000, // Auto-refetch every 30 seconds
+  });
+
+  // Set up real-time subscriptions
+  useEffect(() => {
+    const channels = [
+      supabase
+        .channel('recent_additions_parks')
+        .on('postgres_changes', { event: 'INSERT', schema: 'public', table: 'parks' }, () => {
+          query.refetch();
+        })
+        .subscribe(),
+      supabase
+        .channel('recent_additions_rides')
+        .on('postgres_changes', { event: 'INSERT', schema: 'public', table: 'rides' }, () => {
+          query.refetch();
+        })
+        .subscribe(),
+      supabase
+        .channel('recent_additions_companies')
+        .on('postgres_changes', { event: 'INSERT', schema: 'public', table: 'companies' }, () => {
+          query.refetch();
+        })
+        .subscribe(),
+      supabase
+        .channel('recent_additions_ride_models')
+        .on('postgres_changes', { event: 'INSERT', schema: 'public', table: 'ride_models' }, () => {
+          query.refetch();
+        })
+        .subscribe(),
+      supabase
+        .channel('recent_additions_photos')
+        .on('postgres_changes', { event: 'INSERT', schema: 'public', table: 'entity_photos' }, () => {
+          query.refetch();
+        })
+        .subscribe(),
+    ];
+
+    return () => {
+      channels.forEach(channel => channel.unsubscribe());
+    };
+  }, [query]);
+
+  // Filter by entity type on client side
+  const filteredData = entityTypeFilter && query.data
+    ? query.data.filter(item => item.entity_type === entityTypeFilter)
+    : query.data;
+
+  return {
+    ...query,
+    data: filteredData,
+  };
+}