fix: restore __root.tsx route (accidentally deleted in 2175c24, breaks web build)

apps/web/src/routes/__root.tsx

@@ -0,0 +1,13 @@
+import { createRootRoute, Outlet } from "@tanstack/react-router";
+import { TanStackRouterDevtools } from "@tanstack/react-router-devtools";
+import { Toaster } from "@/components/ui/sonner";
+
+export const Route = createRootRoute({
+  component: () => (
+    <div className="min-h-screen bg-background text-foreground">
+      <Outlet />
+      <Toaster />
+      {import.meta.env.DEV && <TanStackRouterDevtools />}
+    </div>
+  ),
+});