feat(auth): RequireAuth route guard

src/auth/RequireAuth.tsx

@@ -0,0 +1,43 @@
+import { Navigate, useLocation } from "react-router-dom";
+import { useAuth } from "./useAuth";
+import type { ReactNode } from "react";
+
+/**
+ * Route guard. Wrap any subtree that requires a logged-in operator:
+ *
+ *   <Route element={<RequireAuth><Layout/></RequireAuth>}>
+ *     <Route path="/" element={<Dashboard />} />
+ *     ...
+ *   </Route>
+ *
+ * Three branches, in priority order:
+ *
+ *   1. `status === "loading"`     → render a centered "Loading…"
+ *      placeholder so we don't bounce the user to /login before the
+ *      cookie has had a chance to prove itself via /api/auth/me.
+ *   2. `status === "unauthenticated"` → redirect to
+ *      `/login?next=<current path+search>`. The Login page reads
+ *      `next` and bounces the operator back here on success.
+ *   3. otherwise                  → render children (status is
+ *      "authenticated").
+ */
+export function RequireAuth({ children }: { children: ReactNode }) {
+  const { status } = useAuth();
+  const location = useLocation();
+  if (status === "loading") {
+    return (
+      <div className="min-h-screen flex items-center justify-center text-muted-foreground text-sm">
+        Loading…
+      </div>
+    );
+  }
+  if (status === "unauthenticated") {
+    return (
+      <Navigate
+        to={`/login?next=${encodeURIComponent(location.pathname + location.search)}`}
+        replace
+      />
+    );
+  }
+  return <>{children}</>;
+}