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

tailwind.config.js

@@ -0,0 +1,52 @@
+/** @type {import('tailwindcss').Config} */
+export default {
+  content: [
+    "./public/**/*.{html,js}",
+    "./public/views/**/*.html",
+    "./public/js/**/*.js"
+  ],
+  darkMode: 'class',
+  theme: {
+    extend: {
+      fontFamily: {
+        mono: ['"JetBrains Mono"', '"Fira Code"', 'Consolas', 'monospace'],
+        sans: ['Inter', 'system-ui', 'sans-serif']
+      },
+      colors: {
+        space: {
+          950: '#09090b',
+          900: '#0f0f11',
+          850: '#121214',
+          800: '#18181b',
+          border: '#27272a'
+        },
+        neon: {
+          purple: '#a855f7',
+          cyan: '#06b6d4',
+          green: '#22c55e',
+          yellow: '#eab308',
+          red: '#ef4444'
+        }
+      }
+    }
+  },
+  plugins: [
+    require('@tailwindcss/forms'),
+    require('daisyui')
+  ],
+  daisyui: {
+    themes: [{
+      antigravity: {
+        "primary": "var(--color-neon-purple)",
+        "secondary": "var(--color-neon-green)",
+        "accent": "var(--color-neon-cyan)",
+        "neutral": "var(--color-space-800)",
+        "base-100": "var(--color-space-950)",
+        "info": "var(--color-neon-cyan)",
+        "success": "var(--color-neon-green)",
+        "warning": "var(--color-neon-yellow)",
+        "error": "var(--color-neon-red)",
+      }
+    }]
+  }
+}