fix: safe status-recommendation flow, MO-016 order independence, brand constant, message codes

- Add a single shared, pure vehicle-status evaluator (app/services/vehicle_status.py)
  used identically by the data-quality scanner, a new non-mutating status-recommendation
  preview endpoint, and a transactional apply endpoint with optimistic-concurrency token
  revalidation -- eliminates the old opaque "calculate and apply" action and the unsafe
  "maintenance + active booking -> auto rented" shortcut. Frontend
  DataQualityIssueDetail.tsx now shows a review/decide/confirm panel with localized
  why/evidence/consequence text in nl-BE/en-GB/fr-BE, with an exact "Change status to
  <status>" confirm action per the brief.
- Fix MO-016 issue-order dependency: resolving the booking-overlap issue before vs.
  after the status-conflict issue now converges on the same final vehicle status,
  proven by test_mo_016_status_conflict_recommendation_is_order_independent.
- Make "Fleet Ops" a non-localizable brand constant (frontend/src/product.ts,
  backend PRODUCT_NAME) via {{productName}} interpolation everywhere the brand name
  appeared in locale prose; add a permanent test guarding against a translation file
  ever defining the brand name or an "appName" key again.
- Convert dynamic backend prose to stable message codes + params: return status
  reasons, audit field/actor-type labels, automation last_error, and search
  section/vehicle/booking/issue results all now carry codes the frontend localizes,
  with raw technical text demoted to a "Technical details" disclosure.
- docs/fleet-ops-correction/: gap audit, i18n inventory, and the vehicle-status
  decision table documenting the evaluator's rules and safe-status principles.

148 backend tests + Ruff + mypy green; Alembic migration verified upgrade/downgrade;
frontend tsc/build and the i18n-coverage Playwright suite green.

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

backend/tests/test_search.py

@@ -11,6 +11,10 @@ def test_search_finds_a_vehicle_by_reference(ops_client):
     assert match is not None
     assert match["label"] == "MO-001"
     assert match["link"] == "/vehicles/MO-001"
+    # The backend must never send localizable prose -- only a stable code plus raw
+    # data params, so the frontend can render it in the operator's selected language.
+    assert match["detail_code"] == "vehicleSummary"
+    assert set(match["detail_params"]) == {"make", "model", "location"}
 
 
 def test_search_finds_a_booking_by_reference(ops_client):
@@ -37,7 +41,21 @@ def test_search_never_returns_data_quality_issues_for_rental_employee(employee_c
 
 def test_search_section_result_visible_to_operations_manager(ops_client):
     result = ops_client.get("/api/v1/search", params={"q": "audit"}).json()
-    assert any(r["type"] == "section" and r["link"] == "/audit" for r in result["results"])
+    match = next(
+        (r for r in result["results"] if r["type"] == "section" and r["link"] == "/audit"), None
+    )
+    assert match is not None
+    # Section results must ship a stable id, not English prose -- the frontend looks up
+    # navigation:items.<id> and search:sections.<id>.detail in the selected locale.
+    assert match["label"] == "audit"
+    assert match["detail_code"] == "audit"
+
+
+def test_search_section_matches_dutch_and_french_terms(ops_client):
+    nl_result = ops_client.get("/api/v1/search", params={"q": "wagenpark"}).json()
+    assert any(r["type"] == "section" and r["link"] == "/vehicles" for r in nl_result["results"])
+    fr_result = ops_client.get("/api/v1/search", params={"q": "réservation"}).json()
+    assert any(r["type"] == "section" and r["link"] == "/bookings" for r in fr_result["results"])
 
 
 def test_search_section_result_hidden_from_rental_employee(employee_client):