xce-build.sh has self-wrapped into nix develop since 028d8f6a; this
skill's two example command blocks still showed the old manual
"nix develop ./src --command bash ..." wrapper, now stale (harmless
since a nested nix develop is a no-op, but misleading documentation).
Simplified both to invoke the script directly, matching README.md's
same cleanup.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GLfB5uWRdmx2WiZSFC7Fm7