feat: add Space route with Tldraw integration and session validation

apps/web/src/routes/space.tsx

@@ -0,0 +1,36 @@
+import { createFileRoute } from "@tanstack/react-router";
+import { useEffect, useMemo } from "react";
+import { Tldraw } from "tldraw";
+import { z } from "zod";
+import "tldraw/tldraw.css";
+import { authClient } from "@/lib/auth-client";
+
+export const Route = createFileRoute("/space")({
+  validateSearch: z.object({
+    id: z.string().optional(),
+  }).parse,
+  component: SpaceRoute,
+});
+
+function SpaceRoute() {
+  const { id } = Route.useSearch();
+  const { data: session, isPending } = authClient.useSession();
+  const navigate = Route.useNavigate();
+
+  useEffect(() => {
+    if (!((session || isPending) && id)) {
+      navigate({
+        to: "/login",
+      });
+    }
+  }, [session, isPending, navigate, id]);
+
+  // Use a stable persistence key so tabs with same id share state locally
+  const persistenceKey = useMemo(() => `space-${id ?? "default"}`, [id]);
+
+  return (
+    <div className="mx-4 mt-4" style={{ position: "relative", inset: 0 }}>
+      <Tldraw inferDarkMode persistenceKey={persistenceKey} />
+    </div>
+  );
+}