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/app/api/routers/data_quality.py

@@ -11,6 +11,7 @@ from app.models.data_quality import DataQualityIssue
 from app.models.inspection import Inspection
 from app.models.vehicle import Vehicle
 from app.schemas import (
+    ApplyRecommendedStatusRequest,
     ApplyRecommendedStatusResult,
     CurrentUser,
     DataQualityIssueDetailOut,
@@ -21,11 +22,14 @@ from app.schemas import (
     ResolveOdometerRegressionRequest,
     ResolveOverlapRequest,
     ScanResultOut,
+    StatusRecommendationOut,
+    VehicleStatusFactsOut,
 )
 from app.services.data_quality import (
     apply_recommended_status,
     defer_issue,
     merge_customers,
+    preview_vehicle_status_recommendation,
     provide_missing_fields,
     reject_issue,
     resolve_booking_overlap,
@@ -241,17 +245,43 @@ def resolve_overlap(
     return _to_out(issue)
 
 
+@router.post(
+    "/issues/{public_ref}/status-recommendation", response_model=StatusRecommendationOut
+)
+def status_recommendation(
+    public_ref: str,
+    db: Session = Depends(get_db),
+    user: CurrentUser = Depends(require_operations_manager),
+) -> StatusRecommendationOut:
+    """Non-mutating preview: computes the recommendation without changing anything,
+    resolving no issue and writing no audit event. Safe to call repeatedly."""
+    _issue, _vehicle, recommendation, token = preview_vehicle_status_recommendation(db, public_ref)
+    return StatusRecommendationOut(
+        current_status=recommendation.current_status,
+        recommended_status=recommendation.recommended_status,
+        recommendation_code=recommendation.recommendation_code,
+        safe_to_apply=recommendation.safe_to_apply,
+        manual_review_required=recommendation.manual_review_required,
+        facts=VehicleStatusFactsOut(**recommendation.facts.as_dict()),
+        blocking_reasons=recommendation.blocking_reasons,
+        recommendation_token=token,
+    )
+
+
 @router.post(
     "/issues/{public_ref}/apply-recommended-status", response_model=ApplyRecommendedStatusResult
 )
 def apply_status(
     public_ref: str,
+    body: ApplyRecommendedStatusRequest,
     db: Session = Depends(get_db),
     user: CurrentUser = Depends(require_operations_manager),
 ) -> ApplyRecommendedStatusResult:
-    issue, applied_status, reason = apply_recommended_status(db, public_ref, user)
+    issue, applied_status, reason_code = apply_recommended_status(
+        db, public_ref, user, body.recommendation_token
+    )
     return ApplyRecommendedStatusResult(
-        issue=_to_out(issue), applied_status=applied_status, reason=reason
+        issue=_to_out(issue), applied_status=applied_status, reason_code=reason_code
     )