[Enhancement] The 'Software Update' dialog should show current version

[goran-w]

The 'Software Update' dialog (which pops up at startup when there's a newer version) currently shows only the new version-number, but not the current version-number. Seeing both would be helpful for understanding how many versions behind we are.

[ozmium]

I think this is a great idea. Could I also request the following things, please?...

• For the 'Software Update' dialog: Please add the date that the new software was released on. Example:

New version of this software is available: v2025.38
Released on: 10 November 2025
You currently have: v2025.34 (10 August 2025)

For reference, this is what the current dialog looks like:

• For the 'About SourceGit' dialog: Please add the date that the current version was released on. Example:

SourceGit: v2025.34
Released on: 10 August 2025

For reference, this is how the current dialog is displayed: