fix: fence concurrent ZIP archive builds

docker/.env.production.example

@@ -27,6 +27,11 @@ WORKER_TASK_CONCURRENCY=4
 WORKER_CONCURRENCY=2
 IMAGE_PROCESSING_CONCURRENCY=4
 
+# Two concurrent 2 GiB ZIP builds require roughly 8 GiB of temporary disk.
+ZIP_BUILD_CONCURRENCY=2
+ZIP_MAX_ENTRIES=200
+ZIP_MAX_UNCOMPRESSED_BYTES=2147483648
+
 # Resource ceilings tuned for an 8-core / 16 GB application host.
 POSTGRES_MEMORY_LIMIT=2g
 REDIS_MEMORY_LIMIT=1g