Replace the figlet "profullstack.com" wordmark with a scaled-down ASCII
rendition of the Profullstack </> mark (derived from the brand image),
shown on the join@ onboarding and the ssh <name>@ hub. Reuses the existing
banner plumbing; the mark is sourced from internal/brand and rendered in
Profullstack red.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
