fix(playable): close release validation lifecycle gaps

script/playable_test.sh

@@ -13,6 +13,8 @@ set -euo pipefail
 set +x
 cd "$(dirname "$0")/.."
 repo="$PWD"
+process_cleanup_grace_seconds=15
+source script/playable_process_cleanup.sh
 app="${MT_PLAYABLE_APP:-}"
 config=""
 output=""
@@ -92,8 +94,11 @@ for index in $(seq 1 "$repeat"); do
   if [ -n "$serverlist" ]; then args+=(--serverlist "$serverlist"); fi
   if [ "$allow" -eq 1 ]; then args+=(--allow-gameplay); fi
   set +e
-  bash script/run_client_gate.sh "${args[@]}" </dev/null
+  bash script/run_client_gate.sh "${args[@]}" </dev/null &
+  child_pid=$!
+  wait "$child_pid"
   code=$?
+  child_pid=""
   set -e
   if [ "$code" -eq 124 ]; then timed_out=1; fi
   # A run that never produced a sealed report is still listed so the release fails loudly.