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.ts

@@ -1,6 +1,7 @@
-import { type RouteConfig, index } from "@react-router/dev/routes";
+import { type RouteConfig, index, route } from "@react-router/dev/routes";
 
 export default [
-  index("routes/home.tsx"),
-  index("routes/stocks.tsx"),
-] satisfies RouteConfig;
+  index("routes/landing.tsx"),
+  route("api/alpaca/account", "routes/api/alpaca/account.ts"),
+  route("stocks", "routes/stocks.tsx"),
+] satisfies RouteConfig;