The per-row "Share to apps" toggle read only the device-local opt-in flag
(nip71MirrorFlags), so a fresh device / cleared cache / other device reported a
video as un-shared even when its NIP-71 mirror events (34235/34236) exist on the
user's relays.
- nip71MirrorService: add batched findMirrors(videos) -> Map<videoRootId,
{mirrored, kinds, duplicate}>, one lookup per root via the SubscriptionManager
chokepoint (no direct pool.list).
- MyVideosController: tag each mirror button with data-mirror-root; after the
synchronous (local-flag) render, refreshMirrorStates() looks up relay truth,
reconciles the local flag to match (flag stays a cache hint), and corrects each
button label. Fire-and-forget; detection failures fall back to the local flag.
- tests/my-videos-mirror-relay-truth.test.mjs: 4 jsdom behavioral tests
(promote unmirrored->shared, clear stale shared, per-row batch reconcile,
button tagging). Build + lint clean; mirror+my-videos suites 48/48.
Co-Authored-By: Claude Opus 4.8 <[email protected]>