feat(claude): idle compaction is configurable per provider instance

Each Claude instance now has a "Compact idle threads" setting: When you
return (the existing Compact chip and resume prompt), Before the cache
expires (the former global beta toggle), or Never. Never hides the chip
and answers Claude's resume prompt with "keep full history".

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
98da75ed79Julius Marminge committed on 10/21/2026, 6:56:43 PMparent0bdf33a
10 files changedLine totals unavailable