The Refresh/Deep Scan buttons already fired a scan, but the card gave no
feedback so it looked dead. Now it mirrors music's dashboard library card:
- a progress section (phase + bar + detail) appears during a scan, driven by
the shared scan events (real percent);
- buttons disable while scanning;
- the card hydrates on load/return — if a scan is already running, video-scan.js
re-emits progress and the card shows it;
- stats refresh when the scan finishes.
Reuses music's .library-status-progress classes. 84 tests green.
be141d0073