Cursdar2: download ældre versioner

This release ships the live-loop overhaul and compare-pane follow-through work.
Highlights:
- Unified bottom live-loop transport bar and scrub timeline
- Progressive loop loading with newest-first backfill and visible progress states
- Quad-pane loop playback now follows loop history instead of only current live data
- Live-loop crash fixes around progressive loading, scrubbing, and view changes
- Local-history loop refreshes on pan/zoom and product changes
Known issue:
- Loop play state does not always carry forward across every tilt/product change yet; that fix is next.