feat: add initial frontend setup with styles, types, and testing framework

- Created a global CSS file for styling the frontend with responsive design.
- Introduced TypeScript types for various entities including Research, Alpha, and Account.
- Implemented Playwright tests for account management and data synchronization workflows.
- Configured TypeScript with strict settings and included necessary libraries.
- Set up Vite as the build tool with React plugin and API proxy configuration.
- Added a Python script to initialize environment variables securely.

.env.example

@@ -0,0 +1,11 @@
+# Generate real values with: python3 scripts/init_env.py
+ADMIN_USERNAME=admin
+ADMIN_PASSWORD=replace-with-a-strong-password-at-least-12-characters
+# Keep URL-safe characters (hex recommended) for the PostgreSQL connection URL.
+POSTGRES_PASSWORD=replace-with-random-hex-password
+# Fernet key: URL-safe base64 encoding of 32 random bytes; independent of passwords.
+ENCRYPTION_KEY=replace-with-generated-fernet-key
+LOCAL_PORT=8080
+# Public deployment only; bare DNS hostname, without scheme or path.
+DOMAIN=alpha.example.com
+# WorldQuant email/password are configured after system login, not in this file.