Gitea's act-style runners execute workflow steps inside a runner
container, so compose's host port-publish (127.0.0.1:8080:8080) is
not reachable from the steps. PR #23's e2e job timed out waiting
for the server even though the container was up and listening.
Move both the health probe and the Playwright run onto rmnet so
they address the server as http://server:8080:
* health probe: docker run --rm --network e2e_rmnet curlimages/curl
* Playwright: new mcr.microsoft.com/playwright-based image, added
as a profile-gated `playwright` service in compose.e2e.yml,
invoked via `docker compose run --rm playwright`. Drops the
setup-node + npm install runner steps.
