CI has been running `prettier --check` against a tree that was never
formatted, so the check reported 63 files and failed every run. Nothing
here is a behaviour change: `pnpm lint` and the four typecheck builds
pass exactly as before.
conduit-bringup-artifacts is added to .prettierignore instead. Those
files are captured bring-up reports, not maintained sources; reflowing
them would only churn a record of what happened.