- TreeLibraryPage: split categories into a mount-only fetch so filter
changes only re-fetch trees (not categories every time)
- Add safeGetItem/safeSetItem/safeRemoveItem helpers in utils.ts to
prevent crashes in private browsing or when storage is unavailable
- Replace raw localStorage calls in ScratchpadSidebar, TreeNavigationPage,
TreeEditorPage, and treeEditorStore with safe wrappers
- Add aria-label to 20 icon-only buttons across 8 component files
for screen reader accessibility
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
