Spike results corrected the spec: ThemeBuilder.gaps is (outer, inner) at
cosmic-theme/src/model/theme.rs:895, lives under CosmicTheme.{Dark,Light}.Builder
rather than CosmicTk, and fans out to two components. Entry therefore carries
targets: &[Target].
34 tests, including the folding property that keeps gaps_out from clobbering
gaps_in. Bare #rrggbb colours rejected: # begins a comment, as in Hyprland.
