feat(api): scaffolding FastAPI con TraceIdMiddleware, /health y routers stub

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

tests/unit/test_health.py

@@ -0,0 +1,24 @@
+"""Tests del endpoint /health y del TraceIdMiddleware."""
+
+from fastapi.testclient import TestClient
+
+from agentforge_core.main import create_app
+
+
+def test_health_responde_ok() -> None:
+    client = TestClient(create_app())
+    r = client.get("/health")
+    assert r.status_code == 200
+    assert r.json() == {"status": "ok"}
+
+
+def test_trace_id_header_se_devuelve_generado() -> None:
+    client = TestClient(create_app())
+    r = client.get("/health")
+    assert r.headers.get("x-trace-id")
+
+
+def test_trace_id_header_se_propaga_si_viene_en_la_request() -> None:
+    client = TestClient(create_app())
+    r = client.get("/health", headers={"X-Trace-Id": "fixed-123"})
+    assert r.headers["x-trace-id"] == "fixed-123"