perf(llm): google sdk imported when the agent is built, in a worker thread through utils.imports.preload

template/{{ part_dir }}/src/utils/imports.py

@@ -0,0 +1,6 @@
+import asyncio
+from importlib import import_module
+
+
+async def preload(module: str) -> None:
+    await asyncio.to_thread(import_module, module)