Fix C# compilation errors in GitHub Actions CI/CD pipeline

[Copilot]

This PR fixes C# syntax errors that were causing the GitHub Actions build to fail with the following error:

D:\a\auto-deploy-tool\auto-deploy-tool\MainWindow.xaml.cs(1700,1): error CS1038: #endregion directive expected

Problem

The build was failing due to unmatched C# region directives in MainWindow.xaml.cs. Specifically:

1. The "辅助方法" (Helper Methods) region starting at line 1360 was missing its corresponding #endregion directive
2. There was an extraneous character at the end of the file after the namespace closing brace

Solution

• Added the missing #endregion directive to properly close the "辅助方法" region before the "Remote IIS Management Helper Methods" region begins
• Removed the extra character that was causing the syntax error at the end of the file

Verification

• All 8 #region directives now have matching #endregion directives
• The file properly ends with the namespace closing brace
• No functional code was modified - this is purely a syntax fix

This change ensures that both the main build workflow and release workflow will complete successfully, as they share the same build steps that were previously failing due to these C# compilation errors.

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