feat(frontend): scaffold Vite+React+TS+Tailwind/ShadCn + Vitest

TDD: App-renders-ThothII test RED then GREEN. ShadCn v4 (base-nova style)
init + button/checkbox/radio-group/textarea/card/dialog/badge/sonner added.
tailwind.config.ts extended with oklch CSS-variable color mapping required
by ShadCn v4 @apply directives. npm test passes; npm run build clean.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/package.json

@@ -0,0 +1,45 @@
+{
+  "name": "thothii-frontend",
+  "private": true,
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "tsc -b && vite build",
+    "preview": "vite preview",
+    "test": "vitest run",
+    "test:watch": "vitest",
+    "e2e": "playwright test"
+  },
+  "dependencies": {
+    "@base-ui/react": "^1.6.0",
+    "@fontsource-variable/geist": "^5.2.9",
+    "@tanstack/react-query": "^5.59.0",
+    "class-variance-authority": "^0.7.1",
+    "clsx": "^2.1.1",
+    "lucide-react": "^1.21.0",
+    "next-themes": "^0.4.6",
+    "react": "^18.3.1",
+    "react-dom": "^18.3.1",
+    "shadcn": "^4.12.0",
+    "sonner": "^2.0.7",
+    "tailwind-merge": "^3.6.0",
+    "tw-animate-css": "^1.4.0",
+    "zustand": "^5.0.0"
+  },
+  "devDependencies": {
+    "@testing-library/jest-dom": "^6.5.0",
+    "@testing-library/react": "^16.0.0",
+    "@testing-library/user-event": "^14.5.0",
+    "@types/react": "^18.3.0",
+    "@types/react-dom": "^18.3.0",
+    "@vitejs/plugin-react": "^4.3.0",
+    "autoprefixer": "^10.4.0",
+    "jsdom": "^25.0.0",
+    "msw": "^2.4.0",
+    "postcss": "^8.4.0",
+    "tailwindcss": "^3.4.0",
+    "typescript": "^5.6.0",
+    "vite": "^6.0.0",
+    "vitest": "^2.1.0"
+  }
+}