feat(devices): add registration, heartbeat, linking, and device tokens

Backend/middleware/device-auth.ts

@@ -0,0 +1,30 @@
+import type { NextFunction, Request, Response } from 'express';
+
+import { verifyDeviceToken } from '../utils/device-token';
+
+const extractBearerToken = (authorizationHeader?: string): string | null => {
+  if (!authorizationHeader || !authorizationHeader.startsWith('Bearer ')) {
+    return null;
+  }
+
+  return authorizationHeader.slice('Bearer '.length).trim();
+};
+
+export const requireDeviceAuth = (req: Request, res: Response, next: NextFunction): void => {
+  const token = extractBearerToken(req.headers.authorization);
+
+  if (!token) {
+    res.status(401).json({ message: 'Missing bearer device token' });
+    return;
+  }
+
+  const payload = verifyDeviceToken(token);
+
+  if (!payload) {
+    res.status(401).json({ message: 'Invalid device token' });
+    return;
+  }
+
+  req.deviceAuth = payload;
+  next();
+};