feat: Enhance security and validation in backend

- Added helmet for security headers and configured content security policy
- Implemented CORS with a whitelist for allowed origins
- Introduced express-validator for input validation in API endpoints
- Set request size limits to prevent DoS attacks
- Added global error handling and 404 response
- Updated TypeScript configuration to use node16 module resolution
- Improved Docker Compose configuration for security and resource limits
- Created a comprehensive .env.example for environment configuration
- Implemented automated security scans in CI/CD with Trivy
- Added cleanup script for debugging ports
- Established a detailed security policy document

frontend/tsconfig.json

@@ -14,7 +14,7 @@
     "forceConsistentCasingInFileNames": true,
     "noFallthroughCasesInSwitch": true,
     "module": "esnext",
-    "moduleResolution": "node",
+    "moduleResolution": "bundler",
     "resolveJsonModule": true,
     "isolatedModules": true,
     "noEmit": true,