Follow-up to the merged #11 PR (which shipped the enum-based catalogue): make
categories user-defined data and the PO T&C a dynamic editor.
- categories are a TermsCategory TABLE (not an enum) — admins add new ones;
- every PO T&C line is catalogued, incl. the previously-fixed boilerplate
(seeded under a "General" category) and an "Others" bucket;
- the PO form is a dynamic editor: "+ Add term", pick a category, type/pick a
clause (components/po/po-terms-editor.tsx), used by new/edit/manager-edit.
Migration: the already-released 20260624140000 migration is untouched; a new
20260624150000 FORWARD migration renames the enum, creates the table, migrates
existing enum clauses onto category rows, adds isDefault/sortOrder + the two
fixed lines under General, and adds PurchaseOrder.terms (JSON snapshot that
supersedes the legacy tc* columns for export/detail; old POs fall back to tc*).
Tests rewritten for category creation + catalogue/default helpers.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
