Looks up the open PR for the pushed branch via the Gitea API using the
workflow token and posts the staging URL once (skips if the same
comment already exists).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
The e2e tests launch chromium, but uv sync only installs the playwright
package, not the browser binaries, so CI failed with "Executable
doesn't exist" for the headless shell.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>