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/ai/base.py

@@ -13,7 +13,7 @@ class AIProvider(ABC):
     @abstractmethod
     async def reply(
         self, inquiry: str, context: Optional[Dict[str, Any]] = None,
-        tone: str = "professional",
+        tone: str = "professional", preference_context: Optional[str] = None,
     ) -> Dict[str, Any]:
         pass
 
@@ -21,6 +21,7 @@ class AIProvider(ABC):
     async def generate_marketing(
         self, product_info: Dict[str, Any], target: str,
         style: str = "professional", language: str = "en",
+        preference_context: Optional[str] = None,
     ) -> Dict[str, Any]:
         pass