feat: add geolocation fields to session and implement geo stats endpoint

- Added country, city, countryCode, latitude, and longitude fields to the Session model.
- Updated geoip service to fetch and store geolocation data based on user IP.
- Created a new admin endpoint to retrieve geolocation statistics, including user counts by country and city.
- Enhanced admin page to display geolocation statistics with expandable city details.
- Introduced caching for geolocation data to optimize performance.

apps/backend/src/generated/prisma/internal/prismaNamespaceBrowser.ts

@@ -111,6 +111,11 @@ export const SessionScalarFieldEnum = {
   updatedAt: 'updatedAt',
   ipAddress: 'ipAddress',
   userAgent: 'userAgent',
+  country: 'country',
+  city: 'city',
+  countryCode: 'countryCode',
+  latitude: 'latitude',
+  longitude: 'longitude',
   userId: 'userId'
 } as const