fix: preserve employee roles on login sync

daily_report/db.py

@@ -68,6 +68,13 @@ class Database:
     def upsert_employees(self, employees: list[dict[str, Any]]) -> None:
         with self._lock, self.connection:
             for employee in employees:
+                role = employee.get("role")
+                if role is None:
+                    existing = self.connection.execute(
+                        "SELECT role FROM employees WHERE feishu_user_id = ?",
+                        (employee["feishu_user_id"],),
+                    ).fetchone()
+                    role = existing["role"] if existing else "staff"
                 self.connection.execute(
                     """
                     INSERT INTO employees (feishu_user_id, name, department, manager, role, active, updated_at)
@@ -85,7 +92,7 @@ class Database:
                         employee["name"],
                         employee.get("department", ""),
                         employee.get("manager", ""),
-                        employee.get("role", "staff"),
+                        role,
                         0 if employee.get("active") is False else 1,
                     ),
                 )