Use category-filtered font and selected-item dropdowns, separate horizontal and vertical alignment, and reuse the border-color palette templates for text color. Persist vertical alignment additively. Follow the established static text-source pattern: https://obsproject.com/kb/text-sources
Add additive defaults and round-trip tests for per-layer text content and formatting. Model the static text source after OBS text-source conventions: https://obsproject.com/kb/text-sources