Update the global Dotlas skills

Bring the machine’s global skill install back in line with the current dotlas/skills catalog: install/refresh everything in the catalog, then remove remnants — skills that were installed from dotlas/skills but have since been renamed or dropped from the catalog. npx skills add never prunes, so remnants accumulate silently.

Run one spine: locate lock → sync → build catalog truth-set → diff for stale → confirm → remove → report.

Two hard rules, both from INTERNAL.md:

• Agent scope is always -a claude-code. Never -a '*' — not for install, not for removal.
• Only ever touch skills whose lock source is dotlas/skills. Skills installed from any other owner (mattpocock/skills, LottieFiles/..., etc.) are out of scope and must never be removed, even if they look unfamiliar.

1. Locate the global lock file