feat(devices): compute effective online status with stale heartbeat ttl

Backend/routes/devices.ts

@@ -7,6 +7,8 @@ import { deviceLinks, devices } from '../db/schema';
 import { requireAuth } from '../middleware/auth';
 import { requireDeviceAuth } from '../middleware/device-auth';
 import { createDeviceToken } from '../utils/device-token';
+import { getEffectiveDeviceStatus } from '../utils/device-status';
+import { getDeviceOnlineStaleSeconds } from '../utils/env';
 
 const router = Router();
 
@@ -126,7 +128,19 @@ router.get('/', requireAuth, async (req, res) => {
     orderBy: [desc(devices.updatedAt)],
   });
 
-  res.json({ count: result.length, devices: result });
+  const now = new Date();
+  const staleAfterSeconds = getDeviceOnlineStaleSeconds();
+  const effectiveDevices = result.map((device) => ({
+    ...device,
+    status: getEffectiveDeviceStatus({
+      status: device.status,
+      lastSeenAt: device.lastSeenAt,
+      now,
+      staleAfterSeconds,
+    }),
+  }));
+
+  res.json({ count: effectiveDevices.length, devices: effectiveDevices });
 });
 
 router.patch('/:deviceId', requireAuth, async (req, res) => {