One test class per Divi write tool on a shared DiviWriteAbilityTestCase;
the 30 tests move verbatim (per-test assertion counts identical). Adds the
ledger T4 test for a TreeEditor::move() StructureRules refusal.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01At3V6SjwbMe6eMzVGW3Hs7
