Changelog:
- forward download progress from background/offscreen workers to content frames
- add progress UI and button state management in Safari Books page script
- emit structured progress callbacks and faster image fetching in SafariBooksDownloader
- sync Firefox bundle with progress plumbing and concurrency improvements
- ignore packaged extension archives
Description:
Expose progress events through the downloader so the content script can present real-time status, including chapter and asset fetching milestones. Added concurrency controls, page detection, and packaging telemetry, while keeping Firefox build behavior in sync and ignoring generated .xpi bundles.
