By: Michael Lynch <git@mtlynch.io>
Make e2e test derivation deterministic Stop copying Playwright run artifacts into the e2e test output. Those files include traces and videos that vary between runs, which caused `nix build .#e2e-tests --rebuild` to fail with a nondeterministic output error even though the tests themselves passed. The derivation now writes a fixed sentinel file after the Playwright check phase succeeds, so the build still proves the tests passed while remaining reproducible.