CopyFolder now streams envelope metadata via Next() in a first pass (dedup +
queue new messages), then streams bodies for new ones in a second pass —
no more blocking Collect of the whole folder with zero feedback, and memory
stays flat (only new-message meta is held).
- imapx: two-pass streaming CopyFolder + CopyDeps.OnScan(scanned,total)
- orchestrator: throttled 'scan' events during the metadata pass
- web: per-account 'scanning folder: X/N' line under the progress bar;
scan events kept out of the log to avoid flooding
Verified on greenmail: idempotency and internal-date preservation still hold.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MMHQTtnQtQqL8muAXHr9kd