feat: add MiniMax-M2.5 and M2.5-highspeed models (#13557)

## Summary

Add MiniMax's latest M2.5 model family to the model registry and update
the default API base URL to the international endpoint for broader
accessibility.

## Changes

- **Add MiniMax-M2.5 models** to `conf/llm_factories.json`:
- `MiniMax-M2.5` — Peak Performance. Ultimate Value. Master the Complex.
  - `MiniMax-M2.5-highspeed` — Same performance, faster and more agile.
- Both support 204,800 token context window and tool calling (`is_tools:
true`).
- **Update default MiniMax API base URL** in `rag/llm/__init__.py`:
- From `https://api.minimaxi.com/v1` (domestic) to
`https://api.minimax.io/v1` (international).
- Chinese users can still override via the Base URL field in the UI
settings (as documented in existing i18n strings).

## Supported Models

| Model | Context Window | Tool Calling | Description |
|-------|---------------|-------------|-------------|
| `MiniMax-M2.5` | 204,800 tokens | Yes | Peak Performance. Ultimate
Value. |
| `MiniMax-M2.5-highspeed` | 204,800 tokens | Yes | Same performance,
faster and more agile. |

## API Documentation

- OpenAI Compatible API:
https://platform.minimax.io/docs/api-reference/text-openai-api

## Testing

- [x] JSON validation passes
- [x] Python syntax validation passes
- [x] Ruff lint passes
- [x] MiniMax-M2.5 API call verified (returns valid response)
- [x] MiniMax-M2.5-highspeed API call verified (returns valid response)

Co-authored-by: PR Bot <pr-bot@minimaxi.com>
Co-authored-by: Jin Hai <haijin.chn@gmail.com>
Co-authored-by: Yingfeng <yingfeng.zhang@gmail.com>

conf/llm_factories.json

@@ -1300,6 +1300,20 @@
             "rank": "810",
             "url": "https://api.minimaxi.com/v1",
             "llm": [
+                {
+                    "llm_name": "MiniMax-M2.5",
+                    "tags": "LLM,CHAT,200k",
+                    "max_tokens": 204800,
+                    "model_type": "chat",
+                    "is_tools": true
+                },
+                {
+                    "llm_name": "MiniMax-M2.5-highspeed",
+                    "tags": "LLM,CHAT,200k",
+                    "max_tokens": 204800,
+                    "model_type": "chat",
+                    "is_tools": true
+                },
                 {
                     "llm_name": "MiniMax-M2.1",
                     "tags": "LLM,CHAT,200k",

rag/llm/__init__.py

@@ -81,7 +81,7 @@ FACTORY_DEFAULT_BASE_URL = {
     SupportedLiteLLMProvider.Anthropic: "https://api.anthropic.com/",
     SupportedLiteLLMProvider.JiekouAI: "https://api.jiekou.ai/openai",
     SupportedLiteLLMProvider.ZHIPU_AI: "https://open.bigmodel.cn/api/paas/v4",
-    SupportedLiteLLMProvider.MiniMax: "https://api.minimaxi.com/v1",
+    SupportedLiteLLMProvider.MiniMax: "https://api.minimax.io/v1",
     SupportedLiteLLMProvider.DeerAPI: "https://api.deerapi.com/v1",
     SupportedLiteLLMProvider.OpenAI: "https://api.openai.com/v1",
     SupportedLiteLLMProvider.n1n: "https://api.n1n.ai/v1",