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/agents.matrix.yml

@@ -0,0 +1,71 @@
+version: 1
+
+roles:
+  leader:
+    can_edit: ["work/", "backlog/", "spec/", "harness/"]
+    cannot_edit: ["src/", "tests/"]
+    responsibilities:
+      - plan
+      - orchestrate
+      - enforce_gates
+      - close_feature
+
+  architect:
+    can_edit: ["spec/", "harness/contracts/", "docs/"]
+    cannot_edit: ["src/", "tests/", "backlog/features.json:status"]
+    responsibilities:
+      - design
+      - update_contracts
+
+  implementer:
+    can_edit: ["src/", "tests/", "work/artifacts/"]
+    cannot_edit:
+      - "backlog/features.json:done"
+      - "work/history.md"
+      - "work/artifacts/*/reviewer.json"
+      - "work/artifacts/*/security.json"
+      - "work/artifacts/*/qa.json"
+      - "work/artifacts/*/leader-close.json"
+    responsibilities:
+      - implement_feature
+      - write_tests
+      - produce_implementer_evidence
+
+  reviewer:
+    can_edit: ["work/artifacts/"]
+    cannot_edit: ["src/", "tests/", "backlog/"]
+    responsibilities:
+      - technical_review
+      - emit_reviewer_verdict
+
+  security:
+    can_edit: ["work/artifacts/"]
+    cannot_edit: ["src/", "tests/", "backlog/"]
+    responsibilities:
+      - sast
+      - dependency_review
+      - secret_scan
+      - emit_security_verdict
+
+  qa:
+    can_edit: ["work/artifacts/"]
+    cannot_edit: ["src/", "tests/", "backlog/"]
+    responsibilities:
+      - acceptance_traceability
+      - integration_e2e_checks
+      - regression_checks
+      - emit_qa_verdict
+
+  documenter:
+    can_edit: ["work/artifacts/", "docs/", "README.md", "HOWTO.md", "platforms/pi/README.md", "harness/contracts/"]
+    cannot_edit: ["src/", "tests/", "backlog/features.json:status"]
+    responsibilities:
+      - document_changes_when_needed
+      - update_docs_api_contracts_user_facing_notes
+      - produce_documenter_evidence
+
+anti_cheat:
+  - "Implementer cannot promote feature to done"
+  - "Done requires reviewer/security/qa approved artifacts"
+  - "Leader close requires verify.sh success"
+  - "Evidence must be on disk; chat-only claims are invalid"