Problem: effect colour labels (26.5) were drawn only on the Effect Controls header; the Timeline's effect rows looked unlabelled.
Fix: an effect group row in the Timeline paints the label colour as a 4 px bar on its left edge (same look as the Effect Controls header) and registers `timeline.group.<uid>.label` with the label's name for agents. Docs: gaps.md row 21 and ui-parity.md updated.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
