New rows no longer accept 4_5 (the builder does not offer it). On update,
the flexType of every non-desktop breakpoint (tablet, phone, …) is
format-checked against the builder list like desktop. Guide updated.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01At3V6SjwbMe6eMzVGW3Hs7
Composer::row uses ColumnWidths::parse; rowWidthsError and its error-state
save/restore are gone. The update width check moves out of
DiviUpdateAbility into ColumnWidths::updateErrors. Behaviour unchanged.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01At3V6SjwbMe6eMzVGW3Hs7