fix: add onError handler to task routes plugin for proper 401 responses

backend/src/routes/tasks.ts

@@ -38,6 +38,20 @@ async function requireSessionOrBearer(request: Request, headers: Record<string,
 }
 
 export const taskRoutes = new Elysia({ prefix: "/api/tasks" })
+  .onError(({ error, set }) => {
+    const msg = error?.message || String(error);
+    if (msg === "Unauthorized") {
+      set.status = 401;
+      return { error: "Unauthorized" };
+    }
+    if (msg === "Task not found") {
+      set.status = 404;
+      return { error: "Task not found" };
+    }
+    console.error("Task route error:", msg);
+    set.status = 500;
+    return { error: "Internal server error" };
+  })
   // GET all tasks - requires session or bearer auth
   .get("/", async ({ request, headers }) => {
     await requireSessionOrBearer(request, headers);