feat: add notification data model and migration

myteamwallet_backend/src/database/migrations/AddNotificationTables.spec.ts

@@ -0,0 +1,38 @@
+describe('AddNotificationTables1785600000000', () => {
+  it('creates the notification and notification_recipient tables with their indexes and foreign keys', async () => {
+    const migrationModule = require('./1785600000000-AddNotificationTables');
+    const migration = new migrationModule.AddNotificationTables1785600000000();
+    const queryRunner = { query: jest.fn() } as any;
+
+    await migration.up(queryRunner);
+
+    const calls: string[] = queryRunner.query.mock.calls.map((c: any) => c[0]);
+    expect(calls).toHaveLength(7);
+    expect(calls.some((sql) => sql.includes('CREATE TABLE "notification"'))).toBe(true);
+    expect(calls.some((sql) => sql.includes('CREATE TABLE "notification_recipient"'))).toBe(
+      true,
+    );
+    expect(calls.some((sql) => sql.includes('IDX_notification_team_id'))).toBe(true);
+    expect(
+      calls.some((sql) => sql.includes('IDX_notification_recipient_notification_id')),
+    ).toBe(true);
+    expect(calls.some((sql) => sql.includes('IDX_notification_recipient_user_id'))).toBe(
+      true,
+    );
+    expect(calls.some((sql) => sql.includes('FK_notification_team'))).toBe(true);
+    expect(calls.some((sql) => sql.includes('FK_notification_recipient_notification'))).toBe(
+      true,
+    );
+  });
+
+  it('drops both tables on down, recipient first to respect the foreign key', async () => {
+    const migrationModule = require('./1785600000000-AddNotificationTables');
+    const migration = new migrationModule.AddNotificationTables1785600000000();
+    const queryRunner = { query: jest.fn() } as any;
+
+    await migration.down(queryRunner);
+
+    const calls: string[] = queryRunner.query.mock.calls.map((c: any) => c[0]);
+    expect(calls).toEqual(['DROP TABLE "notification_recipient"', 'DROP TABLE "notification"']);
+  });
+});