fix(docker): use WindMagi offline operator UUID

scripts/start-test-server.sh

@@ -62,8 +62,15 @@ if [[ "$plugins" != *"TreeFeller"* ]]; then
   exit 1
 fi
 
-# This is idempotent and confirms the requested local test account is an operator.
-docker compose -f "$compose_file" exec -T minecraft rcon-cli 'op WindMagi' >/dev/null
+# Offline mode assigns a deterministic UUID that differs from the account's online UUID.
+# Verify the exact identity instead of issuing `op WindMagi`, which can resolve online identity.
+offline_uuid="6a3b6e9f-1a2f-380c-8a75-7a7ca6392c0e"
+ops_json="$(docker compose -f "$compose_file" exec -T minecraft sh -lc 'cat /data/ops.json')"
+if [[ "$ops_json" != *'"name": "WindMagi"'* || "$ops_json" != *"\"uuid\": \"${offline_uuid}\""* ]]; then
+  echo "$ops_json" >&2
+  echo "WindMagi's offline-mode UUID was not installed as an operator." >&2
+  exit 1
+fi
 
 cat <<'MESSAGE'
 Tree Feller test server is ready at localhost:25565.