Python 3.10 Compatibility Issue #12

Summary: The project is set up to support Python ≥3.10 in pyproject.toml but uses Python 3.11+ exclusive features, causing import errors when running tests on Python 3.10.

Environment

• Python Version: 3.10.16
• Package Manager: uv 0.7.19
• OS: Linux

Steps to Reproduce

1. Set up Python 3.10 environment:

   uv venv --python 3.10
   uv sync
   uv pip install -e .

2. Run tests:

   uv run pytest tests/ -v

Expected Behavior

Tests should run successfully on Python 3.10 as specified in requires-python = ">=3.10".

Actual Behavior

Tests fail with import errors for Python 3.11+ features:

ImportError: cannot import name 'assert_never' from 'typing'
ImportError: cannot import name 'StrEnum' from 'enum'

Root Cause

Two incompatible imports using features added in Python 3.11:

• StrEnum from enum module
• assert_never from typing module

Affected Files

• chatkit/errors.py:2 - from enum import StrEnum
• chatkit/agents.py:13 - assert_never import in typing imports
• chatkit/server.py - assert_never import (inferred from test output)