feat: implement frontend with TDD (Part 8)

- Scaffold Vite + React 19 + TypeScript strict project
- Neumorphic dark design system (Tailwind v3, amber/orange LED accents)
- Zustand stores for auth (persist) and UI state (notifications, sidebar)
- TanStack Query v5 hooks for server CRUD operations
- WebSocket hook with reconnection backoff and query invalidation
- Components: StatusLed, Sidebar, ServerCard, LoginPage, DashboardPage
- Protected routing with auth guard
- Axios client with JWT interceptor and 401 redirect
- 68 tests across 11 test files (89% statement coverage, 90% function coverage)
- TDD workflow: RED validated, GREEN achieved, coverage verified

frontend/src/vite-env.d.ts

@@ -0,0 +1,10 @@
+/// <reference types="vite/client" />
+
+interface ImportMetaEnv {
+  readonly VITE_API_URL: string;
+  readonly VITE_WS_URL: string;
+}
+
+interface ImportMeta {
+  readonly env: ImportMetaEnv;
+}