Actor stick figures follow edge paints
Why
After the v0.1.1 PlantUML paint pass, boxed participants and notes followed host
dark mode, but actor stick figures still vanished: limb strokes were bound to
color.border.primary, which Valentus dark mode sets to a near-invisible
hairline. Mermaid sequence diagrams had the same gap for .actor-man circle
and line paints (concrete white fill in Mermaid’s stylesheet).