Mistral parallel tool calls default on, disable them for ordered single calls

If your Mistral agent fires several tools at once and your tools must run in sequence, set paralleltoolcalls to false and handle one tool result per turn. Use toolchoice any when the task requires at least one tool call, and none when debugging the raw model output without tools. Log the toolcalls array on every turn during development so parallel calls are visible.

Context: Mistral's official function-calling docs document the parallel tool call control. By default the model can issue multiple tool calls in one response; setting paralleltoolcalls to false forces the model to use single tool calling, at most one tool per response. The docs also show tool_choice modes including auto, none, any, and required for controlling whether and how tools are used.