Migrate OWASP Nest to Zappa for serverless deployment

**Description:**

We want to migrate the OWASP Nest application to **AWS Lambda using Zappa** to enable a serverless deployment model. This migration should aim to make the application **scalable, stateless, and cloud-native**, while keeping existing functionality intact.

**High-level goals:**

* Deploy the Django + Ninja backend to AWS Lambda using Zappa.
* Serve static and media files via **S3** using `django-storages`.
* Use **RDS/Aurora** as the backend database, with connection pooling (RDS Proxy).
* Replace long-running tasks and background jobs with **Lambda-compatible async tasks** or offload to a separate worker (e.g., RQ on ECS/Fargate).
* Update environment and secrets management to use **AWS Parameter Store or Secrets Manager**.
* Configure logging, monitoring, and CloudWatch integration.
* Create a CI/CD pipeline for automatic deployments with `zappa deploy/update`.

**Acceptance criteria:**

1. A fully functional OWASP Nest backend running on AWS Lambda via Zappa.
2. Static/media files served from S3.
3. Background tasks handled in a Lambda-compatible way.
4. Deployment pipeline configured and tested.
5. Documentation updated with deployment instructions.

**Describe alternatives you've considered**

https://github.com/OWASP/Nest/discussions/933 which is not feasible w/o AWS credits.