refactor(LibChecker, AutoLib): 重构 LibChecker 类中 canRenew 方法的返回值类型：

将 canRenew 方法的返回值类型指定为 tuple(bool, dict)，并随之修改返回值以及调用
模块的调用逻辑。

src/operators/AutoLib.py

@@ -252,7 +252,8 @@ class AutoLib(MsgBase):
                 result = 2
         # renewal
         if run_mode["auto_renewal"] and result == 2:
-            if record := self.__lib_checker.canRenew():
+            can_renew, record = self.__lib_checker.canRenew()
+            if can_renew:
                 if self.__lib_renew.renew(username, record, reserve_info):
                     if self.__lib_checker.postRenewCheck(record):
                         result = 0

src/operators/LibChecker.py

@@ -309,7 +309,7 @@ class LibChecker(LibOperator):
 
     def canRenew(
         self
-    ):
+    ) -> tuple[bool, dict]:
 
         # only check the current date
         date = time.strftime("%Y-%m-%d", time.localtime())
@@ -326,12 +326,13 @@ class LibChecker(LibOperator):
             )
             if abs(time_diff_seconds) < 120*60:
                 self._showTrace(f"{trace_msg}, 可以续约")
-                return record
+                return True, record
             else:
                 self._showTrace(f"{trace_msg}, 无法续约")
-                return None
+                return False, None # we do not need to return the record, because if current
+                # time is not available for renewal, the record is not required
         self._showTrace(f"用户在 {date} 没有有效预约记录, 无法续约")
-        return None
+        return False, None
 
 
     def postRenewCheck(