Fix MiniMax-M3 Anthropic-compatible requests so OpenClaw no longer sends the disabled-thinking payload that makes M3 return empty content. M3 defaults now stay on MiniMax's omitted/adaptive thinking path, explicit `/think off` is still respected, and MiniMax-M2.x keeps the disabled-thinking default that prevents reasoning_content leaks.
Also wires the MiniMax thinking policy through bundled provider-policy loading so pre-runtime and configless embedded-agent paths resolve the same defaults.
Thanks @IamVNIE for the live MiniMax API repro and initial patch.