feat: 修复 H5 底部导航覆盖 + 更新项目进度文档

## H5 底部导航修复 (Bug #10)
- 精简 App.vue，移除重复 tabbar，仅保留全局样式
- uni-page 设置 height: calc(100% - 50px) + overflow-y: auto
- 内容区域精确停在底部导航上方，独立滚动不再叠加
- 恢复 custom-tab-bar 组件

## 项目进度文档
- PROGRESS.md 更新至 10 个 Bug 修复
- 新增 H5 底部导航修复记录
- 新增历史变更条目

backend/app/services/marketing.py

@@ -16,13 +16,14 @@ class MarketingService:
         style: str = "professional",
         language: str = "en",
         count: int = 3,
+        preference_context: Optional[str] = None,
     ) -> List[Dict[str, Any]]:
         results = []
         styles = self._get_style_variants(style, count)
 
         for s in styles:
             try:
-                result = await self.ai.marketing(product_info, target, s, language)
+                result = await self.ai.marketing(product_info, target, s, language, preference_context)
                 results.append({
                     "content": result.get("content", ""),
                     "style": s,