TabContribution gains an optional iconColor honoured by the icon rail:
full-strength when active/hovered, dimmed (70%) when idle, so the tint
reads as identity without outshouting the active-state border. The
Claude Activity tab sets claudeAccent (#D97757) — nominative use per the
licenses.yaml trademark note (it marks Claude's own panel).
Filed and closed as a try-it-out (user request); trivially revertible if
the accent doesn't land visually.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>