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.

src/config/env.spec.ts

@@ -0,0 +1,78 @@
+import { loadEnv } from './env';
+
+describe('loadEnv', () => {
+  const valid = {
+    DATABASE_URL: 'postgresql://user:pass@localhost:5432/tracking',
+    JWT_ACCESS_SECRET: 'test-secret-at-least-32-chars-long!!',
+  };
+
+  it('loads required values with defaults', () => {
+    const env = loadEnv(valid);
+
+    expect(env.DATABASE_URL).toBe(valid.DATABASE_URL);
+    expect(env.JWT_ACCESS_SECRET).toBe(valid.JWT_ACCESS_SECRET);
+    expect(env.PORT).toBe(3000);
+    expect(env.JWT_ACCESS_EXPIRES_IN).toBe('15m');
+    expect(env.JWT_ACCESS_EXPIRES_IN_MS).toBe(15 * 60 * 1000);
+    expect(env.REFRESH_TOKEN_EXPIRES_IN_MS).toBe(7 * 24 * 60 * 60 * 1000);
+    expect(env.BCRYPT_SALT_ROUNDS).toBe(10);
+    expect(env.DEFAULT_TIMEZONE).toBe('GMT+7');
+  });
+
+  it('throws when DATABASE_URL is missing', () => {
+    expect(() =>
+      loadEnv({ JWT_ACCESS_SECRET: valid.JWT_ACCESS_SECRET }),
+    ).toThrow('DATABASE_URL is not configured');
+  });
+
+  it('throws when JWT_ACCESS_SECRET is missing', () => {
+    expect(() => loadEnv({ DATABASE_URL: valid.DATABASE_URL })).toThrow(
+      'JWT_ACCESS_SECRET is not configured',
+    );
+  });
+
+  it('throws when JWT_ACCESS_SECRET is a placeholder', () => {
+    expect(() =>
+      loadEnv({
+        DATABASE_URL: valid.DATABASE_URL,
+        JWT_ACCESS_SECRET: 'change-me-to-a-long-random-secret',
+      }),
+    ).toThrow('known placeholder');
+  });
+
+  it('throws when JWT_ACCESS_SECRET is too short', () => {
+    expect(() =>
+      loadEnv({
+        DATABASE_URL: valid.DATABASE_URL,
+        JWT_ACCESS_SECRET: 'short-secret',
+      }),
+    ).toThrow('at least 32 characters');
+  });
+
+  it('parses optional numeric overrides', () => {
+    const env = loadEnv({
+      ...valid,
+      PORT: '4000',
+      BCRYPT_SALT_ROUNDS: '12',
+      REFRESH_TOKEN_EXPIRES_IN_MS: '3600000',
+      JWT_ACCESS_EXPIRES_IN: '5m',
+      DEFAULT_TIMEZONE: 'GMT+0',
+    });
+
+    expect(env.PORT).toBe(4000);
+    expect(env.BCRYPT_SALT_ROUNDS).toBe(12);
+    expect(env.REFRESH_TOKEN_EXPIRES_IN_MS).toBe(3_600_000);
+    expect(env.JWT_ACCESS_EXPIRES_IN).toBe('5m');
+    expect(env.JWT_ACCESS_EXPIRES_IN_MS).toBe(5 * 60 * 1000);
+    expect(env.DEFAULT_TIMEZONE).toBe('GMT+0');
+  });
+
+  it('rejects invalid JWT_ACCESS_EXPIRES_IN format', () => {
+    expect(() =>
+      loadEnv({
+        ...valid,
+        JWT_ACCESS_EXPIRES_IN: '900',
+      }),
+    ).toThrow('must match');
+  });
+});