refactor(pages): 引入 Page Object 模式重构全部页面模块，变量统一为 snake_case

将原始 Selenium 操作脚本重构为三层 Page Object 架构：
- Page Objects（LoginPage/ReserveView/RecordsView/MainShell）
- Component Objects（Overlay 基类 + SeatMapOverlay/ReserveResultDialog 等对话框）
- Flow 状态机（ReserveFlow/CheckinFlow/RenewFlow）
- Services（CaptchaHandler/ReserveValidator/RecordChecker）

变量命名统一为 snake_case，方法名保持 camelCase，类名保持 PascalCase。

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/pages/flows/CheckinFlow.py

@@ -0,0 +1,94 @@
+# -*- coding: utf-8 -*-
+"""
+Copyright (c) 2026 KenanZhu.
+All rights reserved.
+
+This software is provided "as is", without any warranty of any kind.
+You may use, modify, and distribute this file under the terms of the MIT License.
+See the LICENSE file for details.
+"""
+import queue
+
+from selenium.common.exceptions import (
+    NoSuchElementException,
+    TimeoutException,
+)
+from selenium.webdriver.remote.webdriver import WebDriver
+
+from base.MsgBase import MsgBase
+from pages.MainShell import MainShell
+from pages._dialogs import CheckinResultDialog
+
+
+class CheckinFlow(MsgBase):
+
+    def __init__(
+        self,
+        input_queue: queue.Queue,
+        output_queue: queue.Queue,
+        driver: WebDriver,
+        shell: MainShell,
+    ) -> None:
+
+        super().__init__(input_queue, output_queue)
+        self._driver: WebDriver = driver
+        self._shell: MainShell = shell
+
+    def execute(
+        self,
+        username: str,
+    ) -> bool:
+
+        if not self._shell.waitCheckinButton():
+            self._showTrace(f"用户 {username} 签到界面加载失败 !", self.TraceLevel.ERROR)
+            return False
+
+        if self._shell.isCheckinButtonDisabled():
+            self._showTrace("签到按钮不可用, 可能不在场馆内, 正在尝试启用......")
+            if not self._shell.enableCheckinButtonByJS():
+                self._showTrace(f"签到按钮启用失败 !", self.TraceLevel.ERROR)
+                return False
+            self._showTrace("签到按钮已启用")
+
+        self._shell.clickCheckinButton()
+
+        try:
+            with CheckinResultDialog(self._driver) as dialog:
+                result_msg = dialog.getResultMessage()
+                if "签到成功" in result_msg:
+                    details = dialog.getDetails()
+                    if details:
+                        if len(details) >= 5:
+                            self._showTrace(
+                                f"\n"
+                                f"      签到成功 !\n"
+                                f"          {details[1]}\n"
+                                f"          {details[2]}\n"
+                                f"          {details[3]}\n"
+                                f"          {details[4]}"
+                            )
+                    else:
+                        self._showTrace(
+                            "\n"
+                            "      签到成功 !\n"
+                            "          未获取到签到详情 !"
+                        )
+                    dialog.clickOk()
+                    self._showTrace(f"用户 {username} 签到成功 !")
+                    return True
+                else:
+                    failure_reason = result_msg.replace("签到失败", "").strip()
+                    self._showTrace(
+                        f"\n"
+                        "      签到失败 !\n"
+                        f"          {failure_reason}"
+                    )
+                    dialog.clickOk()
+                    self._showTrace(f"用户 {username} 签到失败 !", self.TraceLevel.ERROR)
+                    return False
+        except (NoSuchElementException, TimeoutException):
+            self._showTrace("签到时发生未知错误 !", self.TraceLevel.ERROR)
+            return False
+        except Exception:
+            self._showTrace("签到时发生未知错误 !", self.TraceLevel.ERROR)
+            return False