feat(webui): add Tailwind build system and refactor frontend architecture

- Replace Tailwind CDN with local build (PostCSS + autoprefixer + daisyui)

- Add CSS build scripts with automatic prepare hook on npm install

- Create account-actions.js service layer with unified response format

- Extend ErrorHandler.withLoading() for automatic loading state management

- Add skeleton screens for initial load, silent refresh for subsequent updates

- Implement loading animations for async operations (buttons, modals)

- Improve empty states and add ARIA labels for accessibility

- Abstract component styles using @apply (buttons, badges, inputs)

- Add JSDoc documentation for Dashboard modules

- Update README and CLAUDE.md with development guidelines

package.json

@@ -13,8 +13,12 @@
     "public"
   ],
   "scripts": {
+    "build:css": "tailwindcss -i ./public/css/src/input.css -o ./public/css/style.css --minify",
+    "watch:css": "tailwindcss -i ./public/css/src/input.css -o ./public/css/style.css --watch",
+    "prepare": "npm run build:css",
     "start": "node src/index.js",
     "dev": "node --watch src/index.js",
+    "dev:full": "concurrently \"npm run watch:css\" \"npm run dev\"",
     "accounts": "node src/cli/accounts.js",
     "accounts:add": "node src/cli/accounts.js add",
     "accounts:list": "node src/cli/accounts.js list",
@@ -57,5 +61,13 @@
     "better-sqlite3": "^12.5.0",
     "cors": "^2.8.5",
     "express": "^4.18.2"
+  },
+  "devDependencies": {
+    "@tailwindcss/forms": "^0.5.7",
+    "autoprefixer": "^10.4.16",
+    "concurrently": "^8.2.2",
+    "daisyui": "^4.12.14",
+    "postcss": "^8.4.32",
+    "tailwindcss": "^3.4.0"
   }
 }