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/models/analytics.py

@@ -0,0 +1,18 @@
+from sqlalchemy import Column, String, Integer, DateTime, Text, Float
+from sqlalchemy.dialects.postgresql import UUID, JSONB
+from datetime import datetime
+from app.database import Base
+import uuid
+
+
+class UsageLog(Base):
+    __tablename__ = "usage_logs"
+
+    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
+    user_id = Column(UUID(as_uuid=True), nullable=False, index=True)
+    team_id = Column(UUID(as_uuid=True), nullable=True, index=True)
+    action = Column(String(100), nullable=False)
+    detail = Column(JSONB, default={})
+    ip_address = Column(String(50))
+    user_agent = Column(String(255))
+    created_at = Column(DateTime, default=datetime.utcnow)