Changes
PR #2135 by octo-patch: feat: upgrade MiniMax default model to M3
- Upgraded the MiniMax default model to M3, making it the new flagship selection.
- Added MiniMax-M3 to the static model list as the first entry, establishing it as the default.
- Retained MiniMax-M2.7 and MiniMax-M2.7-highspeed as available alternative models.
- Removed deprecated models (M2.5, M2.5-highspeed, M2.5-lightning, M2, M2.1, and M2.1-lightning) from the static list.