Update every setup step to write completed_steps to .ktx/setup/state.json
instead of ktx.yaml, stripping legacy entries from config on write.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Align stdout informational messages in setup flows with the existing
Clack prompt visual style by prefixing them with │.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>