Refresh the AI index after a pull that changed tracked files

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.

git_pull_execute.sh

@@ -357,6 +357,43 @@ elif [[ "$SYNC_SUCCESS" == true ]]; then
     fi
 fi
 
+# ==============================================================================================
+# ━━━ AI Index Refresh ━━━
+# ==============================================================================================
+#
+# A pull is the only thing that changes tracked files on a server — prod never edits them — so
+# it is the only moment the AI index can go stale. A timer would be the wrong shape: it would
+# do nothing 23 times a day and still drift from the pull that matters.
+#
+# Staleness is invisible in the answers themselves. The index keeps returning the old text with
+# full confidence and correct-looking citations, so a day of drift means the assistant quoting
+# code that no longer exists. That is why this runs here rather than being left to a human.
+#
+# Three gates, any of which skips it: the pull must have succeeded, AI_INDEX_ON_PULL must be
+# true, and AI_ENABLED must be true. ai_index.sh also refuses on its own unless AI_ENABLED is
+# exactly "true", so a node with AI off never pays for this even if the flags disagree.
+#
+# Never fatal. Indexing is an enhancement; a git pull must not be reported as failed because an
+# embedding call timed out.
+if [[ "$DRY_RUN" == true ]]; then
+    [[ "${AI_INDEX_ON_PULL:-false}" == "true" ]] && warn "DRY RUN — would refresh the AI index"
+elif [[ "$SYNC_SUCCESS" == true \
+        && "${AI_INDEX_ON_PULL:-false}" == "true" \
+        && "${AI_ENABLED:-false}" == "true" ]]; then
+
+    _AI_INDEX="$TARGET_DIR/AI/ai_index.sh"
+    if [[ -f "$_AI_INDEX" ]]; then
+        log "Refreshing AI index (incremental — unchanged files are skipped)..."
+        if bash "$_AI_INDEX" >/dev/null 2>&1; then
+            echo "  AI index refreshed"
+        else
+            warn "AI index refresh failed — answers may cite outdated code until it is rerun"
+        fi
+    else
+        warn "AI_INDEX_ON_PULL is true but $_AI_INDEX not found — skipping"
+    fi
+fi
+
 # ==============================================================================================
 # ━━━ Summary ━━━
 # ==============================================================================================