Add Silent Mode option to AutoUpdater

[LegendTheDeveloper]

Introduces a 'Silent' property to AutoUpdater for hiding the download dialog. When enabled, the DownloadUpdateDialog is minimized, hidden from the taskbar, and not visible, allowing updates to proceed without user interaction.

Now you can enable Silent Mode with AutoUpdater.Silent = true;

[Copilot]

Pull Request Overview

This PR introduces a Silent Mode feature to the AutoUpdater library that allows updates to proceed without showing the download dialog to users. The feature is controlled by a new Silent property that, when enabled, hides the download dialog interface.

• Adds a new Silent static property to the AutoUpdater class
• Modifies the DownloadUpdateDialog constructor to hide the dialog when Silent mode is enabled

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
AutoUpdater.cs	Adds the new Silent boolean property with documentation
DownloadUpdateDialog.cs	Implements silent mode behavior by hiding the dialog when the property is enabled