Eager imports of mlflow cause cascading failures on Windows

[ClayGendron]

Problem

databricks_langchain imports mlflow eagerly at module level in genie.py:3, which triggers mlflow's entire import chain including pyspark. This causes failures on Windows due to pyspark 4.x incompatibility.

Import chain

from databricks_langchain import ChatDatabricks
  → databricks_langchain.genie imports mlflow
  → mlflow.types.schema imports pyspark
  → pyspark crashes on Windows (UnixStreamServer)

Environment

• Windows 11
• Python 3.13.3
• databricks-langchain==0.11.0
• mlflow==2.22.4
• pyspark==4.1.1

Suggested fix

Lazy-load mlflow only when GenieAgent is actually used, not at module import time.