Set up PostgreSQL database configuration and enhance application structure

- Added .env.example with database connection details and JWT configuration.
- Introduced docker-compose.yml for PostgreSQL service setup with health checks.
- Created drizzle.config.ts for database schema and migration management.
- Updated nest-cli.json to include Swagger plugin configuration for API documentation.
- Enhanced package.json with new database-related scripts and dependencies.
- Implemented initial database migrations for user and token management.
- Configured application bootstrap process to load environment variables and set up Swagger.
- Added shared application configuration in configure-app.ts for consistent setup.
- Included unit tests for application configuration and Swagger setup.

test/swagger.e2e-spec.ts

@@ -0,0 +1,78 @@
+import { INestApplication } from '@nestjs/common';
+import { Test, TestingModule } from '@nestjs/testing';
+import request from 'supertest';
+import { App } from 'supertest/types';
+import { AppModule } from '../src/app.module';
+import { configureApp } from '../src/common/configure-app';
+
+describe('Swagger (e2e)', () => {
+  describe('when enabled', () => {
+    let app: INestApplication<App>;
+
+    beforeAll(async () => {
+      const moduleFixture: TestingModule = await Test.createTestingModule({
+        imports: [AppModule],
+      }).compile();
+
+      app = moduleFixture.createNestApplication();
+      configureApp(app, {
+        NODE_ENV: 'test',
+        SWAGGER_ENABLED: 'true',
+      });
+      await app.init();
+    });
+
+    afterAll(async () => {
+      await app.close();
+    });
+
+    it('GET /docs returns HTML UI', async () => {
+      const res = await request(app.getHttpServer()).get('/docs').expect(200);
+      expect(res.text).toContain('Swagger UI');
+    });
+
+    it('GET /docs-json includes auth paths', async () => {
+      const res = await request(app.getHttpServer())
+        .get('/docs-json')
+        .expect(200);
+
+      const body = res.body as {
+        paths: Record<string, unknown>;
+        components: { securitySchemes: Record<string, unknown> };
+      };
+
+      expect(body.paths['/auth/login']).toBeDefined();
+      expect(body.paths['/auth/me']).toBeDefined();
+      expect(body.paths['/auth/register']).toBeDefined();
+      expect(body.components.securitySchemes['access-token']).toBeDefined();
+    });
+  });
+
+  describe('when production and not explicitly enabled', () => {
+    let app: INestApplication<App>;
+
+    beforeAll(async () => {
+      const moduleFixture: TestingModule = await Test.createTestingModule({
+        imports: [AppModule],
+      }).compile();
+
+      app = moduleFixture.createNestApplication();
+      configureApp(app, {
+        NODE_ENV: 'production',
+      });
+      await app.init();
+    });
+
+    afterAll(async () => {
+      await app.close();
+    });
+
+    it('GET /docs returns 404', () => {
+      return request(app.getHttpServer()).get('/docs').expect(404);
+    });
+
+    it('GET /docs-json returns 404', () => {
+      return request(app.getHttpServer()).get('/docs-json').expect(404);
+    });
+  });
+});