support extended thinking in tools

[solodov]

using tools with thinking models is currently not supported, for example using opus:thinking with any tool results in:

Error: Failed to call chat-completions api

Caused by:
    messages.1.content.0.type: Expected `thinking` or `redacted_thinking`, but found `text`. When `thinking` is enabled, a final `assistant` message must start with a thinking block (preceeding the lastmost set of `tool_use` and `tool_result` blocks). We recommend you include thinking blocks from previous turns. To avoid this requirement, disable `thinking`. Please consult our documentation at https://docs.claude.com/en/docs/build-with-claude/extended-thinking (type: invalid_request_error)