feat(scheduler): run wake pushes every five minutes

Add db.getAll for registered tokens and tick the interval with
sendPushToDevice per device, with error logging on tick failure.

src/db/fcmTokens.ts

@@ -55,6 +55,11 @@ export const db = {
     await save(all);
   },
 
+  async getAll(): Promise<StoredRow[]> {
+    const all = await load();
+    return Object.values(all);
+  },
+
   async getByFcmToken(fcmToken: string): Promise<StoredRow | undefined> {
     const all = await load();
     return all[fcmToken];

src/scheduler.ts

@@ -1,11 +1,21 @@
+import { db } from "./db/fcmTokens.js";
+import { sendPushToDevice } from "./services/pushService.js";
+
 let intervalId: ReturnType<typeof setInterval> | undefined;
 
 export function startScheduler(): void {
   if (intervalId !== undefined) return;
-  // TODO: replace with job queue or cron for wake-up checks
-  intervalId = setInterval(() => {
-    // placeholder tick
-  }, 60_000);
+
+  intervalId = setInterval(async () => {
+    try {
+      const devices = await db.getAll();
+      for (const d of devices) {
+        await sendPushToDevice(d.fcmToken);
+      }
+    } catch (err) {
+      console.error("scheduler tick failed", err);
+    }
+  }, 5 * 60 * 1000);
 }
 
 export function stopScheduler(): void {