feat: add MiniMax M3 model

[octo-patch]

Reason: add target provider/model to existing provider registry

Summary

• Add MiniMax-M3 to the built-in MiniMax provider model list.
• Include MiniMax-M3 in the MiniMax capability registry for streaming and tool calls.

Test plan

• yarn workspace @janhq/web-app lint
• git diff --check
• secret scan on diff

🤖 Generated with Claude Code

[octo-patch]

Updated the MiniMax registry so MiniMax-M3 is exposed with vision support, and refreshed the MiniMax-M2.7 context description. I added focused capability coverage and ran the model tests (50 passed), ESLint, and the web-app TypeScript build.

[octo-patch]

This PR has been replaced by #8424. The replacement is rebuilt from the latest main with a clean commit history and complete MiniMax endpoint coverage.