feat(booth): live lane busy/free barrier lights from camera vehicle detection

A Hikvision vehicle detection (eventType=VMD, targetType=vehicle) on a
camera bound to entry/exit now marks that lane "busy" and shows it as a
barrier light beside the scan input on the booth (green=free, red=busy).
Advisory only — it gates nothing (never blocks a ticket or opens a barrier).

- Parse eventState (active/inactive) from the Hik payload.
- LaneStatus tracker: a vehicle `active` event marks the camera's bound lane
  busy + arms an auto-clear timer. This camera class sends no leave/`inactive`
  signal, so "free" is timeout-driven (LANE_BUSY_TTL_MS, default 90s; the
  camera re-fires `active` while a car sits there, refreshing the timer). A
  "both"-direction camera marks both lanes.
- Push lane-status over the existing booth WS (+ in the hello snapshot);
  live-store holds { entry, exit }; two BarrierLight icons render it.
- i18n booth.laneEntry/laneExit (sq + en).

Tests: lane-status.test.ts (7 — busy/free, TTL auto-clear, timer re-arm,
no re-emit while busy, both/exit direction, unknown device). server 120/120;
web + server build/lint green.

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

apps/web/src/lib/live-store.ts

@@ -10,6 +10,12 @@ import type { DeviceStatus, LedgerEvent, Occupancy } from "../api.js";
 /** Connection state of the booth WebSocket, for a status indicator in the UI. */
 export type WsStatus = "connecting" | "open" | "closed";
 
+/** Per-lane busy/free from camera vehicle detection (advisory barrier lights). */
+export interface LaneStatus {
+  entry: boolean; // true = busy
+  exit: boolean; // true = busy
+}
+
 /** Cap the in-memory live feed so a long-running booth session can't grow it
  *  unbounded — the full history is always available via the /api/events query. */
 const MAX_FEED = 200;
@@ -23,6 +29,8 @@ interface LiveState {
   /** Live device status keyed by device id (for the footer): set from the WS
    *  hello snapshot, then upserted per device on each device-status push. */
   devices: Record<string, DeviceStatus>;
+  /** Per-lane busy/free (camera vehicle detection). Null until the first WS hello. */
+  lanes: LaneStatus | null;
   setStatus: (s: WsStatus) => void;
   setOccupancy: (o: Occupancy) => void;
   pushEvent: (e: LedgerEvent) => void;
@@ -30,6 +38,8 @@ interface LiveState {
   setDevices: (list: DeviceStatus[]) => void;
   /** Upsert one device's status (a device-status push). */
   upsertDevice: (d: DeviceStatus) => void;
+  /** Set lane busy/free (WS hello + each lane-status push). */
+  setLanes: (l: LaneStatus) => void;
   reset: () => void;
 }
 
@@ -45,6 +55,7 @@ export const useLiveStore = create<LiveState>((set) => ({
   occupancy: null,
   feed: [],
   devices: {},
+  lanes: null,
   setStatus: (status) => set({ status }),
   setOccupancy: (occupancy) => set({ occupancy }),
   pushEvent: (e) =>
@@ -54,5 +65,6 @@ export const useLiveStore = create<LiveState>((set) => ({
     })),
   setDevices: (list) => set({ devices: byId(list) }),
   upsertDevice: (d) => set((s) => ({ devices: { ...s.devices, [d.deviceId]: d } })),
-  reset: () => set({ status: "connecting", occupancy: null, feed: [], devices: {} }),
+  setLanes: (lanes) => set({ lanes }),
+  reset: () => set({ status: "connecting", occupancy: null, feed: [], devices: {}, lanes: null }),
 }));