feat: add AWS Lambda deployment target

[PAMulligan]

Summary

Adds AWS Lambda as Nerva's third deployment target, alongside Cloudflare Workers and Node.js/Docker. Generated projects deploy as a single Lambda function behind an API Gateway HTTP API (payload format 2.0) via AWS SAM, with esbuild producing a single-file bundle and GitHub OIDC handling CI/CD credentials.

Closes #32

Changes

• setup-project.sh --lambda — new platform branch: copies SAM/esbuild/compose templates, adds build:lambda + deploy package scripts, local dev via src/dev.ts (@hono/node-server), writes .env.example, drops the OIDC deploy workflow into .github/workflows/, and generates README sections with cold start optimization notes and the Lambda Web Adapter container alternative
• templates/aws-lambda/ — template.yaml (SAM, AWS::Serverless::HttpApi, nodejs22.x on arm64, 512 MB, $default catch-all route), samconfig.toml, esbuild.config.mjs, docker-compose.yml (local Postgres), deploy.yml (GitHub Actions with OIDC — id-token: write, aws-actions/configure-aws-credentials, setup-sam)
• templates/snippets/aws-lambda/ — typechecked app sources including the Lambda entry point:

  import { handle } from 'hono/aws-lambda';
  import app from './index.js';
  export const handler = handle(app);

• CI — new "Type-check AWS Lambda snippets" step (tsconfig.lambda.json); templates/aws-lambda added to the required-dirs check
• Skills/config/docs — deployment-config-generator gains Step 2c (SAM + esbuild + OIDC patterns), schema-intake target unions and interview updated, pipeline.config.json gains awsLambda block, target mentions updated across CLAUDE.md/README/onboarding/pipeline docs

Deviations from the issue

1. The issue asks for an @hono/aws-lambda dependency — that package does not exist. Hono ships the adapter inside core hono as hono/aws-lambda, so no new runtime dependency is needed (only esbuild as a dev dependency in generated projects).
2. Bundling uses a plain esbuild script + sam deploy rather than sam build, whose esbuild builder shells out to npm and conflicts with pnpm projects.

Test plan

• bash -n + shellcheck (CI severity) on setup-project.sh; JSON validation of all touched configs
• tsc --noEmit passes for all three snippet tsconfigs (cloudflare, node, lambda)
• Generated a real --lambda project: 20/20 Vitest tests pass; pnpm build:lambda emits dist/lambda.mjs; invoking the bundled handler with a simulated API Gateway v2 $default event returns the app's 200 response
• Regressions: real --node project (20/20 tests, no leaked lambda scripts) and --cloudflare dry-run unchanged
• YAML validation of deploy.yml, docker-compose.yml, and edited ci.yml

🤖 Generated with Claude Code