feat(F-003): HTTP foundation with request context and error envelope

- request_id generated or sanitized-propagated on every request (x-request-id)
- structured JSON logging (pino), one correlated line per request, injectable logger
- error envelope v2 { error: { statusCode, code, message, details? }, requestId }
- 5xx messages always generic; stack traces stay in server logs only
- explicit parseJson (zod) input validation hook at the API layer
- README HTTP contract section; deps justified in spec/tech.md
- all gates approved; verify.sh green

work/runtime-status.json

@@ -6,6 +6,6 @@
   "state": "waiting",
   "next_agent": "leader",
   "waiting_for": "Seleccionar una feature pending y actualizar este estado",
-  "updated_at": "2026-08-14T20:00:16Z",
+  "updated_at": "2026-08-14T20:13:28Z",
   "timeline": []
 }