refacto: Keeping entrypoints clean and making files by purpose

server/middleware/auth.js

@@ -0,0 +1,18 @@
+import jwt from "jsonwebtoken";
+
+export const JWT_SECRET = process.env.JWT_SECRET ?? "dev_secret_change_me";
+
+export function authMiddleware(req, res, next) {
+  const authHeader = req.headers["authorization"];
+  if (!authHeader || !authHeader.startsWith("Bearer ")) {
+    return res.status(401).json({ error: "unauthorized" });
+  }
+  const token = authHeader.slice(7);
+  try {
+    const payload = jwt.verify(token, JWT_SECRET);
+    req.user = payload;
+    next();
+  } catch {
+    return res.status(401).json({ error: "invalid_token" });
+  }
+}