The Playwright backend harness now aborts if something else (e.g. the
compose stack) is already on :8080, instead of letting reuseExistingServer
silently point every journey at the wrong backend with the wrong seed —
the failure mode that surfaced mid-restyle. Also gitignore the local
data/ blob-store artifacts.
Co-Authored-By: Claude Fable 5 <[email protected]>