feat: 操作日志系统 + 日期修复 + 协同去重 + 主题持久化 + 计划自动完成

本次累积提交包含以下功能：

1. 修复：el-date-picker 缺失 value-format 导致日期保存偏移（8处）
2. 新增：协同拜访 visit_group_id 去重机制（完整副本 + 周报合并 + 亮灯去重）
3. 新增：计划自动完成（创建计划检测已有拜访 / 编辑拜访触发）
4. 新增：拜访表单选择客户后自动预填过期计划内容
5. 新增：移动端主题切换按钮 + 后端持久化
6. 新增：操作日志系统 (audit_logs)，全覆盖 8 个模块 CRUD
7. 新增：PC端「我的数据」支局长/领导视角客户经理列

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

backend/app/api/key_visits.py

@@ -10,6 +10,7 @@ from app.models.customer import Customer
 from app.models.user import User
 from app.schemas.key_visit import KeyVisitCreate, KeyVisitUpdate, KeyVisitOut
 from app.utils.edit_log import compute_diff, append_entry, init_entry
+from app.utils.audit import log_audit
 
 router = APIRouter(prefix="/key-visits", tags=["KeyVisits"])
 
@@ -69,6 +70,21 @@ async def create_key_visit(
     db.add(k)
     await db.commit()
     await db.refresh(k)
+    # Audit log
+    cust = await db.execute(select(Customer.name).where(Customer.id == k.customer_id))
+    await log_audit(db, "key_visit", k.id, f"{cust.scalar_one_or_none() or ''} ({k.urgency_level})", "create", current_user["user_id"], current_user["name"])
+    await db.commit()
+    return await _enrich(k, db)
+
+
+@router.get("/{item_id}")
+async def get_key_visit(item_id: str, db: AsyncSession = Depends(get_db), current_user: dict = Depends(get_current_user)):
+    result = await db.execute(select(KeyVisit).where(KeyVisit.id == item_id))
+    k = result.scalar_one_or_none()
+    if not k:
+        raise HTTPException(status_code=404, detail="Not found")
+    if current_user["role"] == "manager" and str(k.manager_id) != current_user["user_id"]:
+        raise HTTPException(status_code=403, detail="Access denied")
     return await _enrich(k, db)
 
 
@@ -95,6 +111,10 @@ async def update_key_visit(
         append_entry(k, current_user["name"], changes, getattr(data, "edit_reason", None))
     await db.commit()
     await db.refresh(k)
+    # Audit log
+    cust = await db.execute(select(Customer.name).where(Customer.id == k.customer_id))
+    await log_audit(db, "key_visit", k.id, f"{cust.scalar_one_or_none() or ''} ({k.urgency_level})", "update", current_user["user_id"], current_user["name"])
+    await db.commit()
     return await _enrich(k, db)
 
 
@@ -110,6 +130,11 @@ async def delete_key_visit(
         raise HTTPException(status_code=404, detail="Not found")
     if current_user["role"] == "manager" and str(k.manager_id) != current_user["user_id"]:
         raise HTTPException(status_code=403, detail="Access denied")
+    cust = await db.execute(select(Customer.name).where(Customer.id == k.customer_id))
+    entity_name = f"{cust.scalar_one_or_none() or ''} ({k.urgency_level})"
     await db.delete(k)
     await db.commit()
+    # Audit log
+    await log_audit(db, "key_visit", uuid.UUID(item_id), entity_name, "delete", current_user["user_id"], current_user["name"])
+    await db.commit()
     return {"detail": "deleted"}