Event log: resolve input_received lane from the firing device

Replace the hardcoded lane: 0 on input_received events with a real
device->lane lookup. A new LaneMap caches lane_devices.id -> lane,
built at startup and refreshed by the setup routes on assign/unassign.
An unmapped device logs lane: -1 + a warning (0 is a real lane) and is
still recorded faithfully (append-only chain).

source stays null for raw inputs by design: it's an IdentitySource
(how a vehicle was identified), not a device field; device provenance
remains in identity. Documented both in the wiki.

apps/server/src/server.ts

@@ -5,6 +5,7 @@ import { createDb, type Db } from "@parking/db";
 import { TOKEN_COOKIE, requireJwtSecret } from "./auth.js";
 import { deviceEvents } from "./device-events.js";
 import { EventLog } from "./event-log.js";
+import { LaneMap } from "./lane-map.js";
 import { PrinterMonitor } from "./printer-monitor.js";
 import { buildSigner } from "./signer.js";
 import { authRoutes } from "./routes/auth.js";
@@ -46,9 +47,15 @@ export async function buildServer(opts: BuildOptions = {}): Promise<FastifyInsta
   // Local username/password login → JWT in an HttpOnly cookie + CSRF cookie.
   await authRoutes(app, db);
 
+  // device id -> lane resolver. Built from lane_devices at startup and refreshed
+  // by setupRoutes on assign/unassign, so device events can be stamped with the
+  // lane the device belongs to (events carry the device id, not a lane).
+  const laneMap = new LaneMap(db);
+  laneMap.refresh();
+
   // Device-agnostic setup: the admin selects devices per lane from the driver
   // catalog at first-run. See wiki/concepts/first-run-setup.md.
-  await setupRoutes(app, db);
+  await setupRoutes(app, db, () => laneMap.refresh());
 
   // Inbound device pushes (e.g. Dingtian Input Link URL → button events),
   // guarded by source-IP allowlist + a shared-secret path token, both read from
@@ -72,10 +79,22 @@ export async function buildServer(opts: BuildOptions = {}): Promise<FastifyInsta
   const eventLog = new EventLog(db, buildSigner(app.log));
   await eventRoutes(app, db, eventLog);
   const unsubscribeInput = deviceEvents.onInput((e) => {
+    // Resolve which lane the device belongs to. -1 marks "device fired but isn't
+    // mapped to a lane" (assigned without a lane, or a stale id) — still recorded
+    // faithfully (the chain is append-only) rather than silently dropped or
+    // mis-stamped as lane 0, which is a real lane.
+    const lane = laneMap.laneFor(e.deviceId) ?? -1;
+    if (lane === -1) {
+      app.log.warn(`input from unmapped device ${e.driverId}:${e.deviceId} — logged as lane -1`);
+    }
     eventLog
       .append({
         type: "input_received",
-        lane: 0, // lane mapping is a TODO — device->lane lookup arrives with setup/lane wiring
+        lane,
+        // `source` is an IdentitySource (wiegand/lpr/qr/ticket/manual) — how a
+        // VEHICLE was identified. A raw input has none, so it stays null. The
+        // device provenance lives in `identity` instead.
+        source: null,
         identity: `${e.driverId}:${e.deviceId} input:${e.input}/${e.edge}`,
         occurredAt: e.at,
       })
@@ -83,7 +102,7 @@ export async function buildServer(opts: BuildOptions = {}): Promise<FastifyInsta
   });
   app.addHook("onClose", async () => unsubscribeInput());
 
-  // TODO: entry flow (input event → signed event → print → relay); map device→lane.
+  // TODO: entry flow (input event → signed event → print → relay).
 
   return app;
 }