Decided during manual testing: the legacy drop-inside zone had zero
height, so drops only worked before/after a node and moves happened by
accident. Sections are re-parented via Edit, as before.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Project object tree with add/edit/delete, drag & drop re-parenting,
context menu and Excel export, 1:1 with the legacy web part. The tree
widgets live in pages/_tree so the works page can reuse them.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>