pack_context widened to carry indexed_at + stale alongside marker
and Citation. LLM-citation construction site now plumbs real values
from upstream SearchHit instead of the Task 6 UNIX_EPOCH placeholder.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Test helper missed the SearchHit field expansion from fb-32 Task 1.
UNIX_EPOCH + false placeholders consistent with the cross-crate
synthetic-mock pattern (hybrid.rs, vector.rs build_hit Task 4 stub).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>