M9: MCP Hub locale/correlation propagation, real Hub health check, fix stale test image

Fixed two concrete gaps in the MCP knowledge-search endpoint: no locale field
existed at all (now nl-BE/en-GB/fr-BE, wired to the knowledge provider's
existing language param), and the correlation ID was always freshly minted,
ignoring any inbound X-Correlation-Id header. Added a shared dependency and
applied it to all four MCP endpoints so Fleet Ops's own audit log preserves
the Hub's real correlation ID end to end.

MCP_HUB_BASE_URL/MCP_PROVIDER_ID were declared in .env.example but never read
anywhere. Since the Hub's own registration is catalog-driven (it never needs
Fleet Ops to push a registration call), wired mcp_hub_base_url for a real Hub
reachability health check instead of an unneeded self-registration call.

Renamed Fleet Ops's own internal audit tool labels mobilityops_* -> fleet_ops_*
(mirrored in contracts/mcp-tools.json with mobilityops_* kept as deprecated
aliases); documented that the live Hub connector's own dotted tool namespace
is a separate, Hub-owned naming layer, deliberately not touched.

Automation page's MCP card now shows real evidence (last tool/client/count/
timestamp, honest no-evidence state) instead of just the registration flag.

Also fixed a real methodology gap found mid-session: compose.yaml's api
service has no bind mount, so `docker compose run --rm api` silently tests a
stale image until rebuilt. Re-ran every local gate after rebuilding; fixed one
genuinely stale test assertion and two lint line-length errors surfaced by
that rebuild. 176 tests passing, ruff clean, mypy clean (50 files).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

backend/tests/test_mcp_integrations.py

@@ -81,6 +81,48 @@ def test_mcp_tool_requests_are_audited(client, ops_client):
     assert events[0]["actor_type"] == "service"
 
 
+def test_search_knowledge_respects_requested_locale(client):
+    response = client.post(
+        "/api/v1/integrations/mcp/search-knowledge",
+        json={
+            "question": "Wat moet ik doen wanneer een voertuig beschadigd terugkomt?",
+            "max_sources": 1,
+            "locale": "nl-BE",
+        },
+        headers=_headers(),
+    )
+    assert response.status_code == 200
+    body = response.json()
+    assert body["evidence_state"] == "grounded"
+
+
+def test_search_knowledge_preserves_inbound_correlation_id(client, ops_client):
+    inbound = "11111111-1111-1111-1111-111111111111"
+    response = client.post(
+        "/api/v1/integrations/mcp/search-knowledge",
+        json={"question": "What must I do when a vehicle returns with damage?", "max_sources": 1},
+        headers={**_headers(client_id="correlation-probe"), "X-Correlation-Id": inbound},
+    )
+    assert response.status_code == 200
+    assert response.json()["correlation_id"] == inbound
+
+    events = ops_client.get("/api/v1/audit", params={"action": "mcp_tool_request"}).json()
+    matching = [e for e in events if e["correlation_id"] == inbound]
+    assert len(matching) == 1
+
+
+def test_operations_summary_mints_correlation_id_when_none_supplied(client, ops_client):
+    response = client.get(
+        "/api/v1/integrations/mcp/operations-summary",
+        headers=_headers(client_id="no-correlation-probe"),
+    )
+    assert response.status_code == 200
+    events = ops_client.get("/api/v1/audit", params={"action": "mcp_tool_request"}).json()
+    matching = [e for e in events if e["actor_label"] == "no-correlation-probe"]
+    assert len(matching) >= 1
+    assert matching[0]["correlation_id"]  # a fresh UUID was minted, not left empty
+
+
 def test_no_write_endpoints_exist_under_mcp_namespace(client):
     for method, path in [
         ("post", "/api/v1/integrations/mcp/vehicles/MO-016"),