Groundwork for Cassette (friend library sharing) that stands on its own:
- A brand-new library (fresh data dir, or a fresh iTunes import) starts
with a "New Tracks" smart playlist: added in the last 3 months, newest
first. Fixed persistent id, so two machines seeding one unsynced share
merge into a single playlist.
- Every non-flat button, the sidebar Library button and the transport
boxes get a very slight top-lit gradient computed from the live palette,
with the chosen color kept exactly at its midpoint.
- Tests pin that individual imports stamp date added = now even for an
old file, and that the iTunes migration keeps the XML's dates.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
