Add a UI scale / density setting in Appearance settings #1502

Pre-submission Checklist

• I have searched existing issues to ensure this hasn't been requested before.
• This request covers a single, specific improvement.
• The issue title is concise and descriptive.

Category

🎨 UI / Design Improvement

Is your feature request related to a problem?

The ui feels too big on my phone. Buttons, cards and spacing take up alot of space so fewer songs fit on screen at once. The only way to fix it right now is changing android's display size, but that shrinks every app not just ArchiveTune.

Proposed Solution

Add a "UI scale" option in settings so users can make the whole interface smaller or bigger. Maybe a slider or a few presets like 85%, 90%, 100% (default), 110%. It should scale text and layout together, and default stays 100% so nothing changes for existing users.

Alternatives Considered

No response

Visual Context & Attachments

No response