refactor: fixed some errors while deploying the cluster

tracks/cka/common.py

@@ -1,7 +1,15 @@
 """Shared helpers for CKA task banks."""
 
 NS = r"""
-mkns() { $K create ns "$1" --dry-run=client -o yaml | $K apply -f - >/dev/null; }
+mkns() {
+  $K create ns "$1" --dry-run=client -o yaml | $K apply -f - >/dev/null
+  # Wait for the namespace's `default` ServiceAccount before returning. The controller creates it
+  # asynchronously, and a Pod applied in the gap is rejected outright:
+  #   error looking up service account <ns>/default: serviceaccount "default" not found
+  # Setups that create a namespace and immediately apply Pods lose that race under load (Q204),
+  # which fails the seed and costs the candidate a whole task. It belongs here, not in each task.
+  for _ in $(seq 1 30); do $K -n "$1" get sa default >/dev/null 2>&1 && return 0; sleep 1; done
+}
 """
 
 def C(name, pts, script):