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>

frontend/src/api/types.ts

@@ -109,6 +109,7 @@ export interface AutomationRun {
   status: string;
   attempts: number;
   last_error: string | null;
+  last_error_code: string | null;
   occurred_at: string;
 }
 
@@ -154,6 +155,8 @@ export interface ReturnPreviewResult {
   resulting_odometer_km: number;
   resulting_vehicle_status: string;
   status_reason: string;
+  status_reason_code: string;
+  status_reason_params: Record<string, string | number>;
   would_create_quality_issue: boolean;
   attention_reasons: string[];
   next_booking_risk: NextBookingRisk | null;
@@ -173,7 +176,27 @@ export interface DataQualityIssueDetail extends DataQualityIssue {
 export interface ApplyRecommendedStatusResult {
   issue: DataQualityIssue;
   applied_status: string;
-  reason: string;
+  reason_code: string;
+}
+
+export interface VehicleStatusFacts {
+  active_booking_refs: string[];
+  overlapping_booking_pairs: string[][];
+  service_threshold_reached: boolean;
+  odometer_km: number;
+  next_service_km: number;
+  open_booking_overlap_issue_ref: string | null;
+}
+
+export interface StatusRecommendation {
+  current_status: string;
+  recommended_status: string | null;
+  recommendation_code: string;
+  safe_to_apply: boolean;
+  manual_review_required: boolean;
+  facts: VehicleStatusFacts;
+  blocking_reasons: string[];
+  recommendation_token: string;
 }
 
 export interface ScanResult {
@@ -183,7 +206,8 @@ export interface ScanResult {
 export interface SearchResultItem {
   type: "vehicle" | "booking" | "data_quality_issue" | "section";
   label: string;
-  detail: string;
+  detail_code: string;
+  detail_params: Record<string, string>;
   link: string;
 }