Second root cause found and fixed: act_runner 0.2.11 predates `runs.using: node24`, so any repo on actions/checkout@v5 died before its first step. Bumped to 0.6.1; Windy-Clone went 4/4 red to 4/4 green. Also upgrades the act-cache note from "watch item" to a confirmed job failure (lstat on a vanished file mid-tar), with the wipe command and the annotated-tag dead end that looks like a wrong checkout but isn't. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>