feat(F-001): scaffold modular monolith skeleton with boundary checker

- TypeScript + Fastify skeleton under project/ (src/modules, shared, infrastructure, app)
- scripts/check-module-boundaries.mjs enforcing module public-API rules (tested with fixtures)
- GET /health endpoint, error envelope without stack leakage
- specs/F-001-scaffold (SPEC/DESIGN/TASKS/TESTS), spec/tech.md dependency justification
- 30-ticket MercadoDeVida roadmap in backlog/features.json, spec/roadmap.md
- All gates approved: reviewer, security, qa; verify.sh green

harness/contracts/handoff.md

@@ -0,0 +1,22 @@
+# Handoff Contract
+
+## Regla anti teléfono-descompuesto
+Los agentes **no** devuelven código en chat. Deben escribir a disco y responder solo:
+- `done -> <ruta>`
+- `blocked -> <ruta>`
+
+## Rutas estándar por feature
+- `work/artifacts/<feature_id>/implementer.md`
+- `work/artifacts/<feature_id>/reviewer.json`
+- `work/artifacts/<feature_id>/security.json`
+- `work/artifacts/<feature_id>/qa.json`
+- `work/artifacts/<feature_id>/documenter.md` (opcional; requerido solo si cambiaron docs/API/contratos/comportamiento user-facing)
+- `work/artifacts/<feature_id>/leader-close.json`
+
+## Campos mínimos de artefactos JSON de gate
+- `feature_id` (string)
+- `agent` (reviewer|security|qa|leader)
+- `verdict` (APPROVED|CHANGES_REQUESTED)
+- `summary` (string)
+- `evidence` (array de comandos/salidas/rutas)
+- `timestamp` (ISO 8601)