AI_INDEX_ON_PULL was designed, defaulted false, and never read by anything —
so nothing has ever rebuilt the index automatically. A pull is the only thing
that changes tracked files on a server, which makes it the only moment the
index can go stale, and a timer would do nothing 23 times a day while still
drifting from the pull that matters.
Staleness is invisible in the answers: the index keeps returning the old text
with confident, correct-looking citations. Gated on pull success, on
AI_INDEX_ON_PULL and on AI_ENABLED, and never fatal — a git pull must not fail
because an embedding call timed out.