Clearer mill cert uploads at scale

Uploading mill certificates in bulk is faster to follow and easier to trust. You can now see where certificates came from, track progress file by file during multi-file uploads, and get clearer feedback if upload limits are hit part-way through.

• Multi-file uploads now show per-file progress, so you can see what’s completed and what’s still running
• Bulk uploads are grouped together and shown as Bulk in the mill cert summary table
• Direct one-off uploads are clearly shown separately
• If rate limits are reached, uploads stop gracefully with a partial-success message so you know what made it through
• Archive (zip file) source labelling is in place and rolling out as part of upcoming archive workflows

Who benefits: teams uploading lots of certificates, especially when handling large batches and needing better traceability.