refactor(pages): 抽取时间选择策略为 TimeSelectMaker，将 Overlay 基类更名为 Dialog

将 findBestTimeOption 中的预约/续约双分支逻辑抽象为策略模式：
- TimeOptionReader 负责从 WebElement 提取时间数据（ReserveTimeReader / RenewTimeReader）
- TimeDecisionMaker 执行纯决策算法，零 Selenium 依赖
- TimeSelectMaker 作为工厂统一创建配置好的决策器
- 共享常量 LIBRARY_CLOSE_MINS 统一收敛至 TimeSelectMaker

同时将 Overlay 基类重命名为 Dialog，SeatMapOverlay 同步更名为 SeatMapDialog，保持命名一致性。

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

src/pages/components/Dialog.py

@@ -0,0 +1,110 @@
+# -*- 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.
+"""
+from selenium.webdriver.remote.webdriver import WebDriver
+from selenium.webdriver.remote.webelement import WebElement
+from selenium.webdriver.support.ui import WebDriverWait
+from selenium.webdriver.support import expected_conditions as EC
+
+
+class Dialog:
+    """
+        Context-managed overlay / modal / dialog on a page.
+
+        Automates the lifecycle: wait for appearance on enter,
+        optionally wait for disappearance on exit.
+    """
+
+    def __init__(
+        self,
+        driver: WebDriver,
+        root_locator: tuple,
+        auto_close_on_exit: bool = True,
+        wait_timeout: float = 3.0,
+    ) -> None:
+
+        self._driver: WebDriver = driver
+        self._root_locator: tuple = root_locator
+        self._auto_close: bool = auto_close_on_exit
+        self._timeout: float = wait_timeout
+
+    def __enter__(
+        self,
+    ) -> "Dialog":
+
+        WebDriverWait(self._driver, self._timeout).until(
+            EC.visibility_of_element_located(self._root_locator)
+        )
+        return self
+
+    def __exit__(
+        self,
+        *args: object,
+    ) -> None:
+
+        if self._auto_close:
+            WebDriverWait(self._driver, self._timeout).until(
+                EC.invisibility_of_element_located(self._root_locator)
+            )
+
+    def _find(
+        self,
+        by: str,
+        value: str,
+    ) -> WebElement:
+
+        return self._driver.find_element(by, value)
+
+    def _findAll(
+        self,
+        by: str,
+        value: str,
+    ) -> list[WebElement]:
+
+        return self._driver.find_elements(by, value)
+
+    def _waitClickable(
+        self,
+        locator: tuple,
+        timeout: float = 2.0,
+    ) -> WebElement:
+
+        return WebDriverWait(self._driver, timeout).until(
+            EC.element_to_be_clickable(locator)
+        )
+
+    def _waitPresence(
+        self,
+        locator: tuple,
+        timeout: float = 2.0,
+    ) -> WebElement:
+
+        return WebDriverWait(self._driver, timeout).until(
+            EC.presence_of_element_located(locator)
+        )
+
+    def _waitVisible(
+        self,
+        locator: tuple,
+        timeout: float = 2.0,
+    ) -> WebElement:
+
+        return WebDriverWait(self._driver, timeout).until(
+            EC.visibility_of_element_located(locator)
+        )
+
+    def _waitAllPresence(
+        self,
+        locator: tuple,
+        timeout: float = 2.0,
+    ) -> list[WebElement]:
+
+        return WebDriverWait(self._driver, timeout).until(
+            EC.presence_of_all_elements_located(locator)
+        )