wren runs its model on one BLAS thread

threadpoolctl scopes the limit to wren.act, so other numpy calls in the
engine keep their threads.

uv.lock

@@ -946,6 +946,7 @@ dependencies = [
     { name = "rich" },
     { name = "sqlmodel" },
     { name = "textual" },
+    { name = "threadpoolctl" },
     { name = "uv" },
     { name = "websockets" },
 ]
@@ -998,6 +999,7 @@ requires-dist = [
     { name = "sentry-sdk", extras = ["fastapi"], marker = "extra == 'server'", specifier = ">=2.20.0" },
     { name = "sqlmodel", specifier = ">=0.0.21,<1.0.0" },
     { name = "textual", specifier = ">=1.0" },
+    { name = "threadpoolctl", specifier = ">=3.5" },
     { name = "uv", specifier = ">=0.5" },
     { name = "websockets", specifier = ">=14" },
 ]
@@ -2840,6 +2842,15 @@ wheels = [
     { url = "https://files.pythonhosted.org/packages/fb/be/35261223d9416a0751cdff1c7b4a6f881387218a12d439fe22fefebc8c04/textual-8.2.8-py3-none-any.whl", hash = "sha256:267375fd402dc8d981457212efa71f0e3365fd17bba144ba9bb3ed7563cb374a", size = 731418, upload-time = "2026-06-30T06:51:26.364Z" },
 ]
 
+[[package]]
+name = "threadpoolctl"
+version = "3.7.0"
+source = { registry = "https://pypi.org/simple" }
+sdist = { url = "https://files.pythonhosted.org/packages/00/dc/6c58154c1c65f758ea979e7139cb76993a9cfc662d14e9be3c4a667cfb77/threadpoolctl-3.7.0.tar.gz", hash = "sha256:61348cfb77d53b9242e0017029244b559b810c142ced65b4e21eeca1843959a7", size = 31961, upload-time = "2026-09-15T15:46:20.263Z" }
+wheels = [
+    { url = "https://files.pythonhosted.org/packages/43/3f/f88a53f60a472b46f4023f56d204dd7de33d34c5d2acbfa0d70a674e639e/threadpoolctl-3.7.0-py3-none-any.whl", hash = "sha256:cd8b60b5641b45c67bbf73c64c843235fc2d8a480c87389f52f5dbee893b86be", size = 26362, upload-time = "2026-09-15T15:46:19.168Z" },
+]
+
 [[package]]
 name = "typer"
 version = "0.21.1"