feat: setup 'web' frontend

web/pages/index/+Page.tsx

@@ -0,0 +1,16 @@
+import { AspectRatio } from "@mantine/core";
+
+export default function Page() {
+  return (
+    <div className="mt-4 flex justify-center h-[calc(100vh-120px)]">
+      <AspectRatio ratio={1.0 / 1.2} w="min(100vh * 1.2, 100vw)" maw="95vw">
+        <canvas
+          className="block border-1 border-yellow-400/50 w-full h-full"
+          style={{
+            boxShadow: "0 0 12px rgba(250, 204, 21, 0.35), 0 0 2px rgba(255, 255, 255, 0.25)",
+          }}
+        />
+      </AspectRatio>
+    </div>
+  );
+}