Date group headers (Pinned, Today, Yesterday, Earlier) are now clickable
to collapse/expand their session lists. Collapsed state persists to
localStorage across page reloads.
- Refactored renderSessionListFromCache to group sessions first, then
render groups with collapsible wrappers
- Extracted _renderOneSession() helper for reuse within group bodies
- Chevron indicator rotates -90deg when collapsed
- Pinned group header keeps its gold color
Inspired by PR #75 (@MartinNielsenDev).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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