Retire NEON-ALLEY.md — the v0.10 handoff brief, fully executed

Internal-only doc (never shipped to npm, never linked, not a build input);
its decisions live in the git history and the shipped demo. The other .md
files are public by design and stay — see them in the README/recipes/skill.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: somejohnbforya