The previous implementation called getBotMatchStats for each bot in a loop,
causing 10,000+ separate database queries when there are many bots. This N+1
query problem caused the pod to exceed memory limits and get OOMKilled,
resulting in CrashLoopBackOff.
Replaced with a single batch query that fetches match stats for all bots at
once, then maps the results to each bot. This reduces database round trips
from O(n) to O(1).
Fixes bead bf-2ws: acb-index-builder CrashLoopBackOff (silent crash after web asset copy)