Watching Firefox for breakage

The weekly watch checks two things independently:

• Theme selectors: run an audit against each channel. If exact ID/class replacements can be patched, open a PR with those fixes and the full report. Otherwise, actionable findings open or update an issue for that channel.
• Screenshot capture: run the standard capture to detect Firefox changes that stop previews from rendering at all. Failures get a separate issue.

Issues close when the associated check is healthy again. Proposed fixes still need review and merging. The default audit uses --strict --no-unused, so custom-property failure checks are not enabled in this workflow.

The generated watch does not save structural snapshots or compare screenshots across Firefox releases. To add that history, compose snapshot, changelog, shot and compare in a custom workflow.