AI-review follow-up on #87467:
- On probe failure, remove the extracted ~/.hermes/node tree and the
node/npm/npx bin links so later installer steps and retry runs start
clean instead of resolving node to a binary that cannot start.
- The termux pkg branch had the same silent-success class: an empty
version probe logged success and set HAS_NODE=true. Degrade with the
binary's own error instead.
cb89872c28