fix: update check preamble exits 1 when up to date — convert all skills to .tmpl
The `[ -n "$_UPD" ] && echo "$_UPD"` line in 5 skills was missing `|| true`,
causing exit code 1 when the update check finds no update (empty $_UPD).
Fix: convert ship/, review/, plan-ceo-review/, plan-eng-review/, retro/ to
.tmpl templates using {{UPDATE_CHECK}} placeholder (same as browse/qa/etc).
All 9 skills now generated from templates — preamble changes propagate everywhere.
Also: regenerates qa/SKILL.md which had drifted from its template, adds 12 tests
validating the update check preamble exits 0 in all skills, removes completed TODO.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>