feat: Update popup

[gravelfreeman]

There's a missed opportunity to show users a popup after the app has been updated.

The popup could include:

• Header: Whatever you want to highlight for certain updates. For now, I suggest linking to the community Discord.
• Changelog(s)
• Footer: Share on Reddit shortcut
• Footer: Star on GitHub shortcut
• Footer: Donation
• Actions: Never show changelogs after updates | Convert to note (aka "Read later") | Close

The changelog content could also differ depending on the user:

• Admin: Full changelog
• User: New features and important fixes only. No rare or minor bug fixes; keep it short.

There's probably a way to automate most of this, although I'm not sure how your changelog pipeline currently works.

Each changelog should have an ID in the database so PN can track which changelogs have already been shown to each user.

This way, if I open PN after missing five updates, it could either:

• Show an aggregated changelog combining everything I've missed.
• Show each missed changelog one after another.

[seals187]

yeah why not, its allways good to see "what changed"