Resolve conflicts with the new gradient and graphic-attributes colour
targets: keep main's targets and menu handling, routed through the new
ColorPicker state; adapt dock/view.rs to `color_picker`.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_013rGmDUNr1hUf4zo1X3dak8