Replace the two hand-rolled Set-of-ids collapse state machines in the category
trees with the shared useCollapsibleGroups hook (a strict superset after #288),
keeping each tree's distinct recursive render and CategoryTree's drag-and-drop
untouched.
- CategoryTree (Categories page): storageKey null + defaultExpanded true, so
every parent opens with no seeding; drops the local Set + collectExpandable.
- CategoryTaxonomyTree + guide page: storageKey null + defaultExpanded false
(collapsed by default); exports a shared TAXONOMY_COLLAPSE_ACCESSORS.
- Fix the guide's button bug: allExpanded = expanded.size > 0 flipped to
"Collapse all" after opening a single node; now uses the hook's correct
allExpanded (every group must be open).
- Also migrate StepDiscover (4th consumer of CategoryTaxonomyTree, same button
bug) onto the hook for a green build and consistency.
Both trees pass a flattened node list to the bulk ops; behaviour preserved:
Categories opens expanded, the guide/wizard open collapsed.
Resolves#290
Generated autonomously by /autopilot run of 2026-07-15
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
