Add Playwright configuration and initial tests for landing page

- Created playwright.config.ts for test configuration
- Added .last-run.json to store test run status
- Implemented landing.test.ts with tests for navbar visibility and navigation
- Removed unused server proxy configuration from vite.config.ts

app/routes/landing.tsx

@@ -0,0 +1,29 @@
+import { Link } from "react-router";
+import Navbar from "../components/Navbar";
+import AlpacaAccountInfo from "../components/AlpacaAccountInfo";
+
+export default function Landing() {
+  return (
+    <div className="min-h-screen bg-gradient-to-br from-gray-50 to-blue-50">
+      <Navbar />
+      {/* Hero Section */}
+      <section className="py-20">
+        <div className="mx-auto max-w-7xl px-6 sm:px-8 lg:px-8">
+          <div className="text-center mb-12">
+            <h1 className="text-4xl font-bold text-gray-900 mb-4">
+              Welcome to AITrader
+            </h1>
+            <p className="text-xl text-gray-600 max-w-2xl mx-auto">
+              Your AI-powered trading dashboard with real-time market insights and portfolio management.
+            </p>
+          </div>
+          
+          {/* Account Info Card */}
+          <div className="max-w-md mx-auto">
+            <AlpacaAccountInfo />
+          </div>
+        </div>
+      </section>
+    </div>
+  );
+}