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/components/Navbar.tsx

@@ -0,0 +1,26 @@
+import { Link } from "react-router";
+
+export default function Navbar() {
+  return (
+    <nav className="border-b border-gray-200 bg-white/90 backdrop-blur-sm sticky top-0 z-50">
+      <div className="mx-auto flex max-w-7xl items-center justify-between px-4 py-4 sm:px-6 lg:px-8">
+        <Link to="/" className="flex items-center gap-3 group">
+          <div className="h-8 w-8 rounded-lg bg-blue-600 flex items-center justify-center transition-transform group-hover:scale-105">
+            <span className="text-white font-bold text-sm">A</span>
+          </div>
+          <span className="text-xl font-bold text-gray-900 group-hover:text-blue-600 transition-colors">
+            AITrader
+          </span>
+        </Link>
+        <div className="hidden items-center gap-8 md:flex">
+          <Link 
+            to="/stocks" 
+            className="text-gray-600 hover:text-blue-600 font-medium transition-colors relative after:absolute after:bottom-[-4px] after:left-0 after:w-0 after:h-0.5 after:bg-blue-600 after:transition-all hover:after:w-full"
+          >
+            Stocks
+          </Link>
+        </div>
+      </div>
+    </nav>
+  );
+}