PydanticAI handles tool_choice natively for Anthropic. The extra_body
hack caused an infinite tool call loop where Claude kept calling the
same tool because tool_choice was forced to "any".
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
All agents now prefer Claude API when ANTHROPIC_API_KEY is configured,
with automatic fallback to Ollama when offline or unconfigured. New
src/anthropic/ module provides model selection via get_model() factory.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>