fix(playable): close release validation lifecycle gaps

script/run_client_gate.sh

@@ -31,6 +31,7 @@ allow_gameplay=0
 required_arch="${MT_PLAYABLE_REQUIRED_ARCH:-arm64}"
 godot_bin="${MT_GODOT:-godot}"
 kill_grace_seconds=10
+source script/playable_process_cleanup.sh
 
 usage() {
   cat <<'EOF'
@@ -162,7 +163,6 @@ stop_proxy() {
     proxy_pid=""
   fi
 }
-trap stop_proxy EXIT
 if [ "$fault_status" = "confirmed" ]; then
   # Loopback proxy in front of the test server for this client only. server.* points at it, so
   # playable exit runs sharing the scenario go through it too; only the soak client requests faults.
@@ -255,6 +255,7 @@ while kill -0 "$child_pid" 2>/dev/null; do
 done
 wait "$child_pid"
 process_code=$?
+child_pid=""
 # The redactor ends at EOF; bound the wait in case a grandchild kept the FIFO open.
 redactor_wait=0
 while kill -0 "$redactor_pid" 2>/dev/null && [ "$redactor_wait" -lt 10 ]; do
@@ -267,6 +268,7 @@ if kill -0 "$redactor_pid" 2>/dev/null; then
 fi
 wait "$redactor_pid"
 redactor_code=$?
+redactor_pid=""
 rm -f "$fifo"
 if [ -n "$sampler_pid" ]; then
   # The sampler stops by itself once the child is gone; bound the wait anyway.
@@ -277,6 +279,7 @@ if [ -n "$sampler_pid" ]; then
   done
   if kill -0 "$sampler_pid" 2>/dev/null; then kill -TERM "$sampler_pid" 2>/dev/null; fi
   wait "$sampler_pid"
+  sampler_pid=""
 fi
 stop_proxy