feat(core): integrate database seeding into server startup

Updates `server.dart` to instantiate and run the `DatabaseSeedingService` after the database connection is established.

This ensures that tables are created and initial data (global fixtures, admin user, app config) is seeded on every server start. The idempotent nature of the seeding operations makes this process safe and reliable for both development and first-time production deployments.

Author: fulleni

lib/src/config/server.dart

@@ -8,6 +8,7 @@ import 'package:ht_api/src/services/auth_token_service.dart';
 import 'package:ht_api/src/services/dashboard_summary_service.dart';
 import 'package:ht_api/src/services/default_user_preference_limit_service.dart';
 import 'package:ht_api/src/services/jwt_auth_token_service.dart';
+import 'package:ht_api/src/services/database_seeding_service.dart';
 import 'package:ht_api/src/services/token_blacklist_service.dart';
 import 'package:ht_api/src/services/user_preference_limit_service.dart';
 import 'package:ht_api/src/services/verification_code_storage_service.dart';
@@ -92,7 +93,17 @@ Future<HttpServer> run(Handler handler, InternetAddress ip, int port) async {
   );
   _log.info('PostgreSQL database connection established.');
 
-  // 3. Initialize Repositories
+  // 3. Initialize and run database seeding
+  // This runs on every startup. The operations are idempotent (`IF NOT EXISTS`,
+  // `ON CONFLICT DO NOTHING`), so it's safe to run every time. This ensures
+  // the database is always in a valid state, especially for first-time setup
+  // in any environment.
+  final seedingService = DatabaseSeedingService(connection: _connection, log: _log);
+  await seedingService.createTables();
+  await seedingService.seedGlobalFixtureData();
+  await seedingService.seedInitialAdminAndConfig();
+
+  // 4. Initialize Repositories
   final headlineRepository = _createRepository<Headline>(
     tableName: 'headlines',
     fromJson: Headline.fromJson,
@@ -135,7 +146,7 @@ Future<HttpServer> run(Handler handler, InternetAddress ip, int port) async {
     toJson: (c) => c.toJson(),
   );
 
-  // 4. Initialize Services
+  // 5. Initialize Services
   const uuid = Uuid();
   const emailRepository = HtEmailRepository(
     emailClient: HtEmailInMemoryClient(),
@@ -167,7 +178,7 @@ Future<HttpServer> run(Handler handler, InternetAddress ip, int port) async {
     appConfigRepository: appConfigRepository,
   );
 
-  // 5. Create the main handler with all dependencies provided
+  // 6. Create the main handler with all dependencies provided
   final finalHandler = handler
       // Foundational utilities
       .use(provider<Uuid>((_) => uuid))
@@ -206,15 +217,15 @@ Future<HttpServer> run(Handler handler, InternetAddress ip, int port) async {
         ),
       );
 
-  // 6. Start the server
+  // 7. Start the server
   final server = await serve(
     finalHandler,
     ip,
     port,
   );
   _log.info('Server listening on port ${server.port}');
 
-  // 7. Handle graceful shutdown
+  // 8. Handle graceful shutdown
   ProcessSignal.sigint.watch().listen((_) async {
     _log.info('Received SIGINT. Shutting down...');
     await _connection.close();