Bump version to 0.4.0

This release has breaking changes (mcp 2.x requirement, removed MCP
websocket transport, proxy no longer loads the bundled example config,
OPTILLM_LOG_LEVEL removed), so bump the minor version instead of 0.3.23.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: claude

optillm/__init__.py

@@ -1,5 +1,5 @@
 # Version information
-__version__ = "0.3.23"
+__version__ = "0.4.0"
 
 import os as _os
 

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "optillm"
-version = "0.3.23"
+version = "0.4.0"
 description = "An optimizing inference proxy for LLMs."
 readme = "README.md"
 license = "Apache-2.0"