feat(vision): surface the recognized plate in the booth UI

The ANPR plate was saved (device_events kind:"read") but had no UI. Extend
GET /api/snapshots/by-identity/:identity to also return plates[] (plate, confidence,
region, direction, snapshotId, at) for that session, and render each as a cyan
"Plate: AA558EE 100%" chip in the SnapshotStrip — so it shows in both the booth
event-detail modal and the pay modal, beside the evidence photo, no separate screen.
Deduped by plate+direction; session:read gated; i18n sq+en.

Verified: by-identity returns plates[] for a seeded read (200, AA558EE 0.999 Albania
entry). Build + lint green.

Claude-Session: https://claude.ai/code/session_01Xcm6ikLgGoCxxHrxtjkk5V

apps/web/src/api.ts

@@ -789,11 +789,22 @@ export interface SnapshotFailure {
   occurredAt: string;
 }
 
+/** A licence plate recognized for this session by the ANPR-on-snapshot path (advisory
+ *  record — see opencv-anpr-service.md). `snapshotId` links to the image it was read from. */
+export interface PlateRead {
+  plate: string;
+  confidence: number | null;
+  region: string | null;
+  direction: "entry" | "exit" | null;
+  snapshotId: string | null;
+  at: string;
+}
+
 /** Snapshot metadata for a session identity (newest first) PLUS failed capture
- *  attempts. Image bytes are at `/api/snapshots/:id` — use that as an <img src>. */
+ *  attempts PLUS any recognized plates. Image bytes are at `/api/snapshots/:id`. */
 export function fetchSnapshots(
   identity: string,
-): Promise<{ snapshots: SnapshotMeta[]; failures?: SnapshotFailure[] }> {
+): Promise<{ snapshots: SnapshotMeta[]; failures?: SnapshotFailure[]; plates?: PlateRead[] }> {
   return apiFetch(`/api/snapshots/by-identity/${encodeURIComponent(identity)}`);
 }