feat: migrate to Hono framework

- Add Hono as HTTP framework for Cloudflare Workers
- Create app.ts with declarative routing and middleware
- Add hono-adapters.ts for auth, rate limit, request ID middleware
- Refactor handlers to use Hono Context signature
- Maintain all existing business logic unchanged

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

package.json

@@ -33,5 +33,8 @@
     "typescript": "^5.7.2",
     "vitest": "^2.1.8",
     "wrangler": "^4.59.3"
+  },
+  "dependencies": {
+    "hono": "^4.11.7"
   }
 }