feat(minimax): add MiniMax-M3, set as default, drop M2.5/M2.1/M2

- Add MINIMAX_M3 = "MiniMax-M3" constant and put it first in MODEL_LIST
- Default MinimaxBot model: MiniMax-M2.7 -> MiniMax-M3
- Keep MiniMax-M2.7 and MiniMax-M2.7-highspeed as legacy options
- Drop MINIMAX_M2_5 / MINIMAX_M2_1 / MINIMAX_M2_1_LIGHTNING / MINIMAX_M2
- Update web console recommended/provider model lists
- Update README capability table and docs/models index (en/zh/ja)
- Update docs/models/minimax.mdx and coding-plan.mdx MiniMax section
- Update run.sh / run.ps1 installer default and menu hint
- Update zh CLI status sample output
- Update unit tests to assert new M3 default and constant

TTS (speech-2.*) and API base URL remain unchanged.

docs/ja/models/coding-plan.mdx

@@ -61,7 +61,7 @@ description: Coding Planモデルの設定
 ```json
 {
   "bot_type": "openai",
-  "model": "MiniMax-M2.5",
+  "model": "MiniMax-M3",
   "open_ai_api_base": "https://api.minimaxi.com/v1",
   "open_ai_api_key": "YOUR_API_KEY"
 }
@@ -69,7 +69,7 @@ description: Coding Planモデルの設定
 
 | パラメータ | 説明 |
 | --- | --- |
-| `model` | `MiniMax-M2.5`、`MiniMax-M2.5-highspeed`、`MiniMax-M2.1`、`MiniMax-M2` |
+| `model` | `MiniMax-M3`、`MiniMax-M2.7`、`MiniMax-M2.7-highspeed` |
 | `open_ai_api_base` | 中国: `https://api.minimaxi.com/v1`、グローバル: `https://api.minimax.io/v1` |
 | `open_ai_api_key` | Coding Plan専用キー（従量課金とは共有不可） |