Use adaptive thinking with Claude Opus 4.6

/app/.venv/lib/python3.12/site-packages/langchain_anthropic/chat_models.py:1410: UserWarning: Using Claude with claude-opus-4-6 and 'thinking.type=enabled' is deprecated. Use 'thinking.type=adaptive' instead which results in better model performance in our testing: https://platform.claude.com/docs/en/build-with-claude/adaptive-thinking

See https://platform.claude.com/docs/en/build-with-claude/adaptive-thinking#supported-models:

thinking.type: "enabled" and budget_tokens are deprecated on Opus 4.6 and Sonnet 4.6 and will be removed in a future model release. Use thinking.type: "adaptive" with the effort parameter instead. If you are already using extended thinking with budget_tokens, it continues to work and no immediate changes are required.

Older models (Sonnet 4.5, Opus 4.5, etc.) do not support adaptive thinking and require thinking.type: "enabled" with budget_tokens.

Start with the warning from langchain_anthropic/chat_models.py and read the linked adaptive-thinking documentation for supported models. Locate where this project configures Claude thinking, then verify that Opus 4.6 uses adaptive thinking while older models retain enabled thinking. Done when the deprecation warning no longer appears for Opus 4.6 and model compatibility is preserved.