Dynamically assigns segment colors by sweeping across the full HSV hue spectrum based on their track position. This ensures each segment has a distinct, predictable hue and removes the need for explicit `color` assignments.
- Replaced fixed calendar timestamps with `minutesAgo()` so beam-store items stay within the 24h working-memory TTL.
- Broadened background-color assertion to match both truecolor (`48;2;`) and 256-palette (`48;5;`) terminals.
- Added unit tests for renderSegmentTrack verifying per-segment coloring, active chip fill formatting, and active-index movement.
- Added tests for theme.getContrastFgAnsi to ensure selected foreground contrast remains clearly readable against RGB fills.
- Removed the OAuth selector keybinding test and its local auth-storage scaffolding, and documented the new model-tier/role-cycle chip-track behavior in the changelog.