refactor: Replace drift by serverpod as core engine (#33)

benchmark/utils/tables.dart

@@ -0,0 +1,31 @@
+// Keeps CRDT scope aligned with integration tests plus the benchmark table.
+
+import 'package:serverpod_database/serverpod_database.dart';
+import 'package:serverpod_offline_sync_test_client/serverpod_offline_sync_test_client.dart';
+
+/// [Types] is benchmark-only; the rest mirrors `client_session.dart` sync scope.
+List<Table> get benchmarkSyncTables => [
+  Address.t,
+  City.t,
+  Company.t,
+  Organization.t,
+  Person.t,
+  Town.t,
+  Types.t,
+  Unique.t,
+  UniqueUuid.t,
+];
+
+Future<void> clearUserTables(DatabaseSession session) async {
+  await session.db.unsafeExecute('PRAGMA foreign_keys = OFF');
+  final result = await session.db.unsafeQuery('''
+    SELECT name
+    FROM sqlite_master
+    WHERE (type = 'table') AND (name NOT LIKE 'serverpod_%')
+''');
+  for (final row in result) {
+    final tableName = row[0] as String;
+    await session.db.unsafeExecute('DELETE FROM "$tableName"');
+  }
+  await session.db.unsafeExecute('PRAGMA foreign_keys = ON');
+}