CLAUDE.md gains the rule (a TaskGuard for every job that runs off the UI
thread and can take more than a moment; no progress window, panel or
toast of its own), and docs/background-tasks.md says how: kind, label,
progress, units, detail, the three ways to cancel, examples and tests.
Photo Merge's and the face scan's docs no longer describe the old
progress toast.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
