fix: 修复主程序卡死与下载器集成，新增真实数据测试

- LookingWebMain: 强制 IPv4 避免 IPv6 不可达挂起；requests 加超时防卡死
- get_seed_from_element_detail: 修复限流页崩溃与 favicon 误作来源 URL，改用 canonical/传入 URL
- QbittorrentDownloader: 修复 main() 中模块/类误用导致的 download_by_seed AttributeError；请求加超时
- MySqlService: 修复数据库不可达时 query/execute/close 的 None 崩溃，close 后置空 connection
- 新增 cf_session: Cloudflare 人机认证 cookie 管理 + 限流退避重试 + 自动弹浏览器刷新验证
- 新增 refresh_cf_cookies.py: 弹出浏览器手动验证并保存 cf_clearance
- tests/: 真实网络/数据库测试（get_page、seed_is_exist、cf_session）+ run_tests.py runner
- 清理无用脚本(final_test2/verify_replace/REPLACEMENT_INFO)，.idea 与 cookie 文件入 .gitignore

注: test_qbittorrent_downloader.py 11 个用例为既有失败（mock 目标 session 为实例属性，与实现错配），未在本次范围

tests/test_database.py

@@ -0,0 +1,75 @@
+"""
+测试 MySQLDatabase 类
+"""
+import pytest
+import pymysql
+from loguru import logger
+import sys
+import os
+
+# 添加项目路径
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..'))
+
+from dataService.MySqlService import MySQLDatabase, DatabaseConfig
+
+
+class TestMySQLDatabase:
+    """MySQLDatabase 类测试"""
+
+    def setup_method(self):
+        """每个测试方法前的设置"""
+        logger.remove()
+        logger.add(sys.stderr, level="DEBUG")
+
+    def test_database_config(self):
+        """测试数据库配置"""
+        assert DatabaseConfig.HOST == "192.168.123.199"
+        assert DatabaseConfig.PORT == 3306
+        assert DatabaseConfig.USER == "root"
+        assert DatabaseConfig.PASSWORD == "GUOxy5157"
+        assert DatabaseConfig.DB == "LookingWeb"
+        logger.info("数据库配置正确")
+
+    def test_create_connection_exists(self):
+        """测试创建连接对象"""
+        connection = MySQLDatabase.create_connection()
+        assert connection is not None
+        logger.info("数据库连接对象创建成功")
+        connection.close()
+
+    def test_connection_has_attributes(self):
+        """测试连接对象有必需的属性"""
+        connection = MySQLDatabase.create_connection()
+        assert hasattr(connection, 'host')
+        assert hasattr(connection, 'port')
+        assert hasattr(connection, 'user')
+        assert hasattr(connection, 'password')
+        assert hasattr(connection, 'db')
+        assert hasattr(connection, 'connection')
+        assert hasattr(connection, 'connect')
+        assert hasattr(connection, 'query')
+        assert hasattr(connection, 'execute')
+        assert hasattr(connection, 'close')
+        logger.info("连接对象具有所有必需的属性和方法")
+        connection.close()
+
+    def test_connection_close(self):
+        """测试关闭连接"""
+        connection = MySQLDatabase.create_connection()
+        connection.close()
+        assert connection.connection is None
+        logger.info("关闭连接成功")
+
+
+def run_tests():
+    """运行所有测试"""
+    pytest.main([
+        __file__,
+        "-v",
+        "--tb=short",
+        "--log-cli-level=INFO"
+    ])
+
+
+if __name__ == "__main__":
+    run_tests()