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/followup.py

@@ -0,0 +1,51 @@
+from sqlalchemy import Column, String, Boolean, Integer, DateTime, Text, ForeignKey
+from sqlalchemy.dialects.postgresql import UUID, JSONB
+from sqlalchemy.orm import relationship
+from datetime import datetime
+from app.database import Base
+import uuid
+
+
+class FollowupStrategy(Base):
+    __tablename__ = "followup_strategies"
+
+    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
+    name = Column(String(255), nullable=False)
+    description = Column(Text)
+    trigger_condition = Column(JSONB, default={
+        "min_silence_days": 3,
+        "max_silence_days": 999,
+        "min_health_score": 0,
+        "max_health_score": 100,
+        "status_filter": ["lead", "negotiating"],
+    })
+    channel = Column(String(50), default="whatsapp")
+    ai_prompt_template = Column(Text)
+    priority = Column(Integer, default=0)
+    is_active = Column(Boolean, default=True)
+    created_at = Column(DateTime, default=datetime.utcnow)
+    updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
+
+
+class FollowupLog(Base):
+    __tablename__ = "followup_logs"
+
+    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
+    user_id = Column(UUID(as_uuid=True), nullable=False, index=True)
+    customer_id = Column(UUID(as_uuid=True), ForeignKey("customers.id"), nullable=False, index=True)
+    strategy_id = Column(UUID(as_uuid=True), ForeignKey("followup_strategies.id"), nullable=True)
+    status = Column(String(50), default="pending")
+    channel = Column(String(50), default="whatsapp")
+    content = Column(Text)
+    ai_generated_content = Column(Text)
+    user_edited_content = Column(Text)
+    health_score_at_time = Column(Integer)
+    silence_days_at_time = Column(Integer)
+    sent_at = Column(DateTime)
+    replied_at = Column(DateTime)
+    response_status = Column(String(50))
+    log_metadata = Column("metadata", JSONB, default={})
+    created_at = Column(DateTime, default=datetime.utcnow)
+    updated_at = Column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow)
+
+    customer = relationship("Customer", backref="followup_logs")