Add AWS Lambda deployment target

[PAMulligan]

Description

Add AWS Lambda as a deployment target. Hono has first-class AWS Lambda adapter support, making this a natural addition to Nerva's deployment options.

Why

AWS Lambda is the most widely used serverless platform in enterprise environments. Many organizations have AWS-centric infrastructure — supporting Lambda deployment lets them adopt Nerva without changing their cloud provider.

Acceptance Criteria

• Add `--lambda` flag to `setup-project.sh`
• Create `templates/aws-lambda/` directory with:
  • SAM template (`template.yaml`) or CDK configuration
  • Lambda handler wrapper using Hono's AWS Lambda adapter
  • API Gateway configuration (HTTP API, not REST API)
• Add `@hono/aws-lambda` dependency
• Generate Lambda entry point:
  ```typescript
  import { handle } from '@hono/aws-lambda';
  import app from './index.js';
  export const handler = handle(app);
  ```
• Update `deployment-config-generator` skill
• Include cold start optimization notes in generated README
• Add CI/CD template for AWS deployment (GitHub Actions with OIDC)
• CI passes

Notes

Consider also supporting AWS Lambda with Lambda Web Adapter for container-based Lambda deployments, which simplifies the setup.