fix: localize dashboard evidence, explain blocked vehicles, clarify pending odometers

Three content defects found by a live reviewer:

- Dashboard attention subtext was raw, untranslated evidence.summary text, and for
  11 of 15 seeded issues that text was literally "Synthetic deterministic seed
  issue". AttentionItem now exposes evidence_signals (stable code + params, same
  shape as the issue detail page) instead of a detail string; the frontend renders
  them through a shared describeEvidenceSignal() used by both the dashboard and the
  issue detail page. Every previously-placeholder seed row now cites a real,
  per-rule-type fact (a genuinely crossed service threshold, a genuinely blank
  field, or a real pair of booking odometer readings) instead of invented prose.

- 5 of 7 blocked vehicles had no quality issue at all and one had only a resolved
  one, so "needs attention" led nowhere. Each now has a real open
  missing_required_field issue backed by a genuinely blank field (no schema change,
  no migration -- reuses the existing data-quality pipeline).

- Booking odometer fields showing a bare "-" for 25 reserved + 1 active booking now
  show a localized explanation ("trip hasn't started yet" / "not yet closed").
  MO-024's rented-but-service-overdue contradiction was already caught by the
  vehicle-status evaluator (DQ-SCAN, vehicle.manual_review_required) -- added a
  regression test rather than new logic.

Also fixed a related bug the above exposed: the vehicle entity_snapshot omitted
registration_number entirely, so the "provide missing fields" form always showed
it blank regardless of the real value.

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

frontend/src/pages/Dashboard.tsx

@@ -12,6 +12,8 @@ import { SeverityBadge, StatusBadge } from "../components/Badge";
 import { Icon } from "../components/Icons";
 import { ErrorState, IntegrationMark, LoadingState, PageHeader, SectionHeading } from "../components/PageChrome";
 import { N8N_STATE_META, MCP_STATE_META } from "../data/integrationLabels";
+import { describeEvidenceSignal } from "../data/evidenceSignals";
+import type { AttentionItem } from "../api/types";
 
 const FLEET_METRIC_KEYS: Array<{ key: keyof DashboardData["metrics"]; labelKey: string; tone: string }> = [
   { key: "available", labelKey: "readiness.available", tone: "ready" },
@@ -29,9 +31,20 @@ function attentionItemTitle(
   return `${ruleLabel} — ${item.link_ref}`;
 }
 
+// The backend never emits prose here either -- only stable signal codes + params, exactly
+// like the data-quality issue detail page. Multiple signals on one item (e.g. the
+// duplicate-customer match) are joined into one readable line for this compact row.
+function attentionItemDetail(
+  t: (key: string, options?: Record<string, unknown>) => string,
+  formatNumber: (value: number) => string,
+  item: Pick<AttentionItem, "evidence_signals">,
+): string {
+  return item.evidence_signals.map((signal) => describeEvidenceSignal(t, formatNumber, signal)).join(" · ");
+}
+
 export function Dashboard() {
-  const { t } = useTranslation(["dashboard", "common", "integrations"]);
-  const { formatTime, formatShortDate } = useLocaleFormat();
+  const { t } = useTranslation(["dashboard", "common", "integrations", "quality"]);
+  const { formatTime, formatShortDate, formatNumber } = useLocaleFormat();
   const greetingPeriod = useGreetingPeriod();
   const { user } = useAuth();
   const { manifest } = useDemoManifest();
@@ -71,9 +84,9 @@ export function Dashboard() {
 
   const attention = useMemo(() => data?.attention_items.filter((item) => {
     const matchesSeverity = severity === "all" || item.severity === severity;
-    const haystack = `${attentionItemTitle(t, item)} ${item.detail} ${item.link_ref}`.toLowerCase();
+    const haystack = `${attentionItemTitle(t, item)} ${attentionItemDetail(t, formatNumber, item)} ${item.link_ref}`.toLowerCase();
     return matchesSeverity && haystack.includes(query.toLowerCase());
-  }) ?? [], [data, query, severity, t]);
+  }) ?? [], [data, query, severity, t, formatNumber]);
 
   const isUnfiltered = severity === "all" && query === "";
   const attentionTiers = useMemo(() => {
@@ -157,7 +170,7 @@ export function Dashboard() {
                           <SeverityBadge severity={item.severity} />
                           <div className="queue-copy">
                             <p className="attention-title">{title}</p>
-                            <p className="attention-detail">{item.detail}</p>
+                            <p className="attention-detail">{attentionItemDetail(t, formatNumber, item)}</p>
                           </div>
                           <span className="queue-ref">{item.link_ref}</span>
                           <Icon name="chevron" className="row-chevron" />