Bound setup Helm wait behavior and align tini usage

Use Helm v4 wait strategy in dev setup, ensure fleet chart jobs
use args (not command) so image ENTRYPOINT `tini --` remains active,
and adjust graceful-shutdown signal tests to assert termination before
waiting for replacement pods.

Author: thardeck

dev/setup-fleet

@@ -36,7 +36,7 @@ if [ -n "$shards_json" ]; then
   done
 fi
 
-helm -n cattle-fleet-system upgrade --install --create-namespace --wait --reset-values \
+helm -n cattle-fleet-system upgrade --install --create-namespace --wait=hookOnly --reset-values \
   --set apiServerCA="$ca" \
   --set apiServerURL="$server" \
   $shards_settings \