updateCategory checks a new parent before writing: the category itself,
one of its descendants or a category caught in a cycle (cycle), a fourth
level counting its sub-tree (too_deep), a parent holding transactions of
its own (parent_has_transactions). The refusal is a CategoryHierarchyError
that the Categories page shows by the translation of its code. The reads
and the writes, the new parent's is_inputable included, run in one
transaction through its handle; an unchanged parent is not checked, so a
category stored before these rules can still be renamed.
getCategoryDepth keeps the ids it has seen and ends on a cycle.
A "Check hierarchy" button, between "All keywords" and "Re-initialize",
opens a window that lists the orphan categories (caught in a parent loop,
parent deleted, parent gone), one per group, with a new parent for each:
the root by default, or a parent of the category form's list.
reattachCategory applies the same rules; after it, the list and the tree
reload and the Journal gets one line with the reason and the number of
categories put back, no name.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
