feat: show recognized plate in live feed + active sessions

Surface the advisory ANPR plate (device_events kind="read", keyed by
session identity — unsigned, prunable, never an access decision) next to
entry/exit events in the live feed and on active-session rows.

Resolved at serialize time (new plate-lookup.ts; prefers an entry read;
one device_events scan per page) like subscriber-name enrichment — the
signed ledger is untouched. Adds plate? to the shared LedgerEvent and to
ActiveSession/SessionLookup; a small amber badge in the UI.

Caveat: a vehicle_entry is signed + pushed over WS before the async ANPR
read lands, so a fresh feed row may show no plate until reload; always
present on active sessions.

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

apps/server/src/pay-station.ts

@@ -2,6 +2,7 @@ import { desc, eq, ledgerEvents, sessions, subscriptions, tariffVersions, tariff
 import { priceSession, type TariffStructure, type Tender } from "@parking/shared";
 import type { FastifyBaseLogger } from "fastify";
 import type { EventLog } from "./event-log.js";
+import { plateForIdentity, platesForIdentities } from "./plate-lookup.js";
 
 // The PAY STATION: a customer pays for an open session BEFORE walking back to the
 // car (pay-on-foot — payment is decoupled from exit). Two steps:
@@ -78,6 +79,9 @@ export interface ActiveSession {
   readonly subscriptionId: string | null;
   /** The subscriber's holder name (for a friendly label instead of the raw key). */
   readonly subscriptionHolder: string | null;
+  /** Advisory licence plate recognized for this session (ANPR-on-snapshot), shown for
+   *  at-a-glance identification. Null when no plate was read. Never an access decision. */
+  readonly plate: string | null;
 }
 
 /** Booth session view: everything the pay/exit modal needs in one read. */
@@ -104,6 +108,9 @@ export interface SessionLookup {
   readonly subscription: boolean;
   readonly subscriptionId: string | null;
   readonly subscriptionHolder: string | null;
+  /** Advisory licence plate recognized for this session (ANPR-on-snapshot). Null when
+   *  none. Display/audit only — never an access decision. */
+  readonly plate: string | null;
 }
 
 export class PayStation {
@@ -243,7 +250,7 @@ export class PayStation {
       return {
         identity: id, found: false, open: false, enteredAt: null, exitedAt: null,
         paidAt: null, amountMinor: null, currency: null, withinGrace: false, graceExpiresAt: null,
-        overstay: false, subscription: false, subscriptionId: null, subscriptionHolder: null,
+        overstay: false, subscription: false, subscriptionId: null, subscriptionHolder: null, plate: null,
       };
     }
     // Subscription occurrence? The entry payload carries permit:true + permitId.
@@ -288,6 +295,7 @@ export class PayStation {
       paidAt, amountMinor, currency, withinGrace, graceExpiresAt, overstay,
       subscription: isSubscription, subscriptionId,
       subscriptionHolder: this.#holderOf(subscriptionId),
+      plate: plateForIdentity(this.#db, id)?.plate ?? null,
     };
   }
 
@@ -337,6 +345,10 @@ export class PayStation {
       }
     }
 
+    // Resolve advisory plates for all candidate identities in ONE device_events scan
+    // (cheaper than one lookup per row).
+    const plates = platesForIdentities(this.#db, byId.keys());
+
     const now = Date.now();
     const out: ActiveSession[] = [];
     for (const [identity, a] of byId) {
@@ -396,6 +408,7 @@ export class PayStation {
         subscription: isSubscription,
         subscriptionId: a.subscriptionId ?? null,
         subscriptionHolder: this.#holderOf(a.subscriptionId ?? null),
+        plate: plates.get(identity)?.plate ?? null,
       });
     }