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.

packages/api-contract/src/admin.ts

@@ -93,3 +93,24 @@ export type AdminBlockUserInput = z.infer<typeof adminBlockUserSchema>
 export type AdminGlobalStats = z.infer<typeof adminGlobalStatsSchema>
 export type AdminPaymentStatus = z.infer<typeof adminPaymentStatusSchema>
 export type AdminUserSession = z.infer<typeof adminUserSessionSchema>
+
+export const adminGeoCitySchema = z.object({
+  city: z.string(),
+  userCount: z.number().int().nonnegative(),
+})
+
+export const adminGeoCountrySchema = z.object({
+  country: z.string(),
+  countryCode: z.string(),
+  totalUsers: z.number().int().nonnegative(),
+  cities: z.array(adminGeoCitySchema),
+})
+
+export const adminGeoStatsSchema = z.object({
+  countries: z.array(adminGeoCountrySchema),
+  totalUniqueCountries: z.number().int().nonnegative(),
+})
+
+export type AdminGeoCity = z.infer<typeof adminGeoCitySchema>
+export type AdminGeoCountry = z.infer<typeof adminGeoCountrySchema>
+export type AdminGeoStats = z.infer<typeof adminGeoStatsSchema>