Capture the regression class behind #748 (orphan el.<removed-field>.addEventListener after a button is removed from index.html): Bun.build is transpile-only so web:check does not catch it, and the runtime crash only surfaces on init.
Adds the minimal closeout checks (grep dist + curl 19666 + control-plane status) and a one-liner orphan listener scan that authors can run while the PR is open.
Refs: pikasTech/HWLAB#748
Codex
e806218184