feat: add `backend-hono` module

[ronak-create]

Summary

Add Hono as a backend option — a lightweight, edge-first HTTP framework with an Express-like API.

Why

Hono has become the go-to choice for projects targeting Cloudflare Workers, Bun, and Deno.
It's the natural pairing for a deployment-cloudflare module (see related issue) and a common request from the community.

---

Files to generate

• src/index.ts — Hono app with CORS, health endpoint, typed routes
• tsconfig.json
• .env.example

---

Implementation hints

• Add packages/modules/src/backend/hono.ts
  → use express.ts as the structural template, swap deps and file content

• Key deps:

  • hono

• The generated entry file should use:

  • export default app (standard for edge runtimes)
  • along with a Node.js serve wrapper

• Conflicts with:

  • other backend modules

• Register in:

  • index.ts
  • registry-loader.ts
  • graph-definition.ts

---

Contributor guidance

Refer to CONTRIBUTING.md → "Adding a New Module"

---

Acceptance criteria

• foundation create lists Hono as a backend option
• Generated src/index.ts type-checks with zero errors
• Snapshot test added