In Updates tab for installs, it should be possible to select the exact version of ComfyUI, for both stable + latest from github

In Stable, should be by tag. In Latest from Github, should be by commit (commit messages would be nice to have).

Since the display for pdates is by latest, we should probably expose this as another button - "Select Version" or something, which will then bring up a modal that will show the versions. When selected (and not he version that is currently installed), there should be Copy & Update and Update buttons in that modal which will then cause the update to start. The progress can be shown in the central pill drawer same as normal updates.

Start with the Updates tab install flow and trace how Stable tags and Latest from GitHub commits are currently discovered and displayed. Define the version-selection modal, including Copy & Update, Update, and progress behavior in the central pill drawer; done means both sources support selecting a non-current exact version and starting the corresponding update.

Written by the indexing model from the issue text.