Adds a dynamic storage projection bar that shows users how their
selections will impact disk space:
- Displays current disk usage and projected usage after installation
- Updates in real-time as users select maps, ZIM collections, and tiers
- Color-coded warnings (green→tan→orange→red) based on projected usage
- Shows "exceeds available space" warning if selections exceed capacity
- Works on both Linux (disk array) and Windows (fsSize array)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
