feat: Phase 7 - Frontend scaffolding and auth (T-023, T-024, T-025)

T-023: Initialize React project
- Vite + React 19 + TypeScript scaffold
- Tailwind CSS v4 with @tailwindcss/vite plugin
- Dependencies: react-router-dom, axios, @tanstack/react-query, lucide-react
- Project structure: api/, components/, pages/, context/, types/, hooks/, lib/

T-024: API client and auth context
- Axios client with JWT interceptor (auto-attach token, clear on 401)
- login() and getMe() API functions
- AuthContext: user state, login, logout, isAuthenticated, isLoading
- Token persistence via localStorage with hydration on mount
- TypeScript types for all backend models

T-025: Login page and layout
- LoginPage with form, error handling, redirect on success
- Layout with sidebar + header + Outlet
- Sidebar with role-aware navigation (System only for admin)
- ProtectedRoute wrapper with role-based access control
- Routes: /login, /dashboard, /techniques, /tests, /system

frontend/vite.config.ts

@@ -0,0 +1,11 @@
+import { defineConfig } from "vite";
+import react from "@vitejs/plugin-react";
+import tailwindcss from "@tailwindcss/vite";
+
+export default defineConfig({
+  plugins: [react(), tailwindcss()],
+  server: {
+    host: "0.0.0.0",
+    port: 5173,
+  },
+});