feat: initialize gateway frontend with Vue 3, Vite, and Tailwind CSS

- Set up pnpm workspace with necessary dependencies including esbuild and vue-demi.
- Create initial HTML structure for the frontend application.
- Implement main App component with Vue Router integration.
- Add global styles using Tailwind CSS and custom theme variables.
- Define TypeScript environment for Vue components.
- Create a default layout component for consistent page structure.
- Set up Vue Router with a home view route.
- Implement authentication store using Pinia for user management.
- Create utility for tRPC client setup.
- Develop HomeView component with login functionality and server status placeholder.
- Configure TypeScript for Node with composite and strict options.
- Set up Vite configuration for Vue and Tailwind CSS integration.

app/gateway-frontend/src/assets/main.css

@@ -0,0 +1,11 @@
+@import "tailwindcss";
+
+@theme {
+  --color-sammo-dark: #1a1a1a;
+  --color-sammo-gold: #ffd700;
+}
+
+body {
+  @apply bg-black text-gray-200;
+  font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, Roboto, 'Helvetica Neue', 'Segoe UI', 'Apple SD Gothic Neo', 'Noto Sans KR', 'Malgun Gothic', 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol', sans-serif;
+}