cli: refresh outdated marked skills on install

`skill install` treated any non-empty SKILL.md as foreign, so a previous
install that no longer matched the embedded TEXT was left stale while
status reported "not installed". Refresh marked files to TEXT; still
never clobber unmarked foreign content.
03432bc2f3Grok Bot committed on 10/5/2026, 5:46:12 PMparentce05ab1

Checks

All checks passed
1 file changedLine totals unavailable