M16: isolate acceptance and harden readiness

backend/tests/test_health.py

@@ -7,3 +7,35 @@ def test_health() -> None:
     response = TestClient(app).get("/health")
     assert response.status_code == 200
     assert response.json() == {"status": "ok", "service": "mobilityops-api"}
+
+
+def test_liveness_is_process_only() -> None:
+    response = TestClient(app).get("/health/live")
+    assert response.status_code == 200
+    assert response.json()["status"] == "ok"
+
+
+def test_readiness_checks_the_canonical_database() -> None:
+    response = TestClient(app).get("/health/ready")
+    assert response.status_code == 200
+    assert response.json() == {
+        "status": "ready",
+        "service": "mobilityops-api",
+        "database": "up",
+    }
+
+
+def test_readiness_degrades_when_database_is_unavailable(monkeypatch) -> None:
+    import app.main as main_module
+
+    class BrokenSession:
+        def __enter__(self):
+            raise ConnectionError("database unavailable")
+
+        def __exit__(self, *_args):
+            return False
+
+    monkeypatch.setattr(main_module, "SessionLocal", BrokenSession)
+    response = TestClient(app).get("/health/ready")
+    assert response.status_code == 503
+    assert response.json()["database"] == "down"