[madhavkhoslaa]

Summary

• Print a lowercase Vapour wordmark with blue particles in interactive root help; keep redirected output plain and command output clean.
• Sync the embedded llm.txt fallback with the current developer handbook, including ZIP scan/verification and the CLI tutorial link.
• Update CLI LLM publishing notes for signed ZIPs and asynchronous verification.

Checks

• go build ./..., go vet ./..., and go test ./... pass (TMPDIR and GOTMPDIR set to the home cache because /tmp hit its quota).
• LLM docs updated in docs/llm/publish.md.

Companion developer-handbook PR follows in vapour-dev-docs.