feat: dist-site 多主题模板 + 中英双语 i18n

- 新增 4 套主题模板：starter/default/dark/minimal
  - Starter: 毛玻璃 + GradientText + SpotlightCard (原有风格)
  - Default: Aurora 极光背景 + SplitText + TiltedCard
  - Dark: Particles 粒子 + DecryptedText 赛博朋克风格
  - Minimal: 极简优雅 + FadeContent 淡入动画
- 新增 i18n 中英双语支持 (i18next + browser-languagedetector)
- 新增 ThemeProvider 运行时主题切换 (根据 theme_template 字段)
- 新增 11 个 react-bits 动画组件
- 所有页面文案国际化 (Login/Register/Dashboard/Tokens/Pricing/Packages)
- 新增 README.md + README.zh.md 含主题切换指南

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

package.json

@@ -12,11 +12,15 @@
   },
   "dependencies": {
     "axios": "^1.7.0",
+    "i18next": "^25.9.0",
+    "i18next-browser-languagedetector": "^8.2.1",
     "motion": "^12.0.0",
+    "ogl": "^1.0.11",
     "react": "^18.3.0",
     "react-dom": "^18.3.0",
-    "react-router-dom": "^6.26.0",
-    "react-hot-toast": "^2.4.1"
+    "react-hot-toast": "^2.4.1",
+    "react-i18next": "^16.5.8",
+    "react-router-dom": "^6.26.0"
   },
   "devDependencies": {
     "@types/react": "^18.3.0",