Initial commit: WYSIWYG Markdown Editor - Go backend + React/TypeScript frontend with Tailwind CSS

Backend:
- Cobra CLI with --data-dir, --port, --host flags
- Gin HTTP server with REST API for markdown CRUD operations
- File storage on disk (.md files only)
- Comprehensive logrus logging
- Backend tests with CRUD round-trip verification

Frontend:
- React 18 + TypeScript + Tailwind CSS
- Markdown editor with live GFM preview (react-markdown + remark-gfm)
- File management UI (list, create, open, save, delete)
- Theme switcher with Dark/Light/System modes
- Responsive design
- Frontend tests with vitest

Testing:
- All backend tests pass (go test ./...)
- All frontend tests pass (npm test)

frontend/package.json

@@ -0,0 +1,42 @@
+{
+  "name": "markdown-editor-frontend",
+  "version": "1.0.0",
+  "description": "Markdown Editor Frontend",
+  "scripts": {
+    "dev": "vite",
+    "build": "tsc && vite build",
+    "preview": "vite preview",
+    "lint": "eslint src --ext ts,tsx",
+    "test": "vitest run",
+    "test:watch": "vitest",
+    "test:ui": "vitest --ui"
+  },
+  "dependencies": {
+    "framer-motion": "^10.18.0",
+    "react": "^18.2.0",
+    "react-dom": "^18.2.0",
+    "react-markdown": "^9.0.0",
+    "remark-gfm": "^4.0.0"
+  },
+  "devDependencies": {
+    "@testing-library/jest-dom": "^6.9.1",
+    "@testing-library/react": "^14.0.0",
+    "@testing-library/user-event": "^14.4.0",
+    "@types/react": "^18.2.0",
+    "@types/react-dom": "^18.2.0",
+    "@typescript-eslint/eslint-plugin": "^6.0.0",
+    "@typescript-eslint/parser": "^6.0.0",
+    "@vitejs/plugin-react": "^4.0.0",
+    "autoprefixer": "^10.4.16",
+    "eslint": "^8.44.0",
+    "eslint-plugin-react": "^7.33.0",
+    "eslint-plugin-react-hooks": "^4.6.0",
+    "eslint-plugin-react-refresh": "^0.4.3",
+    "jsdom": "^28.0.0",
+    "postcss": "^8.4.31",
+    "tailwindcss": "^3.3.3",
+    "typescript": "^5.0.0",
+    "vite": "^4.4.0",
+    "vitest": "^0.34.0"
+  }
+}