Create example project: Todo API (Cloudflare Workers)

[PAMulligan]

Description

Create a complete example project demonstrating Nerva's Cloudflare Workers deployment path. A Todo API is the "Hello World" of REST APIs — simple enough to learn from, complex enough to showcase CRUD, validation, and auth patterns.

Why

New users need a working reference implementation to understand how all the pieces fit together. The README mentions three quick-start paths, but there are no concrete example projects to examine. A Todo API on Cloudflare Workers is the most requested developer experience for edge computing.

Acceptance Criteria

• Create examples/todo-api-cloudflare/ directory
• Include a complete, working API with:
  • CRUD endpoints for todos (GET /todos, POST /todos, GET /todos/:id, PUT /todos/:id, DELETE /todos/:id)
  • Drizzle schema with D1 database
  • Zod request/response validation
  • Integration tests (Vitest)
  • wrangler.toml configuration
  • Proper TypeScript strict mode
• Include a README.md with:
  • Prerequisites
  • Setup instructions
  • API endpoint documentation
  • How to deploy to Cloudflare Workers
• Generated using Nerva's setup-project.sh --cloudflare as the starting point
• All tests pass
• Add link from the main README's Quick Start section

Notes

This should serve as a reference implementation that contributors can point to when answering "how does this work?" questions.