Feat stepfun (#1659)

### What problem does this PR solve?

#1661
#1660

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

---------

Co-authored-by: lijianyong <lijianyong@stepfun.com>

conf/llm_factories.json

@@ -1895,7 +1895,7 @@
             "llm": [
                 {
                     "llm_name": "step-1-8k",
-                    "tags": "LLM,CHAT,15k",
+                    "tags": "LLM,CHAT,8k",
                     "max_tokens": 8192,
                     "model_type": "chat"
                 },
@@ -1916,6 +1916,12 @@
                     "tags": "LLM,CHAT,256k",
                     "max_tokens": 262144,
                     "model_type": "chat"
+                },
+                {
+                    "llm_name": "step-1v-8k",
+                    "tags": "LLM,CHAT,IMAGE2TEXT",
+                    "max_tokens": 8000,
+                    "model_type": "image2text"
                 }
             ]
         },

rag/llm/chat_model.py

@@ -85,7 +85,6 @@ class MoonshotChat(Base):
         if not base_url: base_url="https://api.moonshot.cn/v1"
         super().__init__(key, model_name, base_url)
 
-
 class XinferenceChat(Base):
     def __init__(self, key=None, model_name="", base_url=""):
         key = "xxx"
@@ -898,9 +897,9 @@ class OpenRouterChat(Base):
         self.model_name = model_name
 
 class StepFunChat(Base):
-    def __init__(self, key, model_name, base_url="https://api.stepfun.com/v1/chat/completions"):
+    def __init__(self, key, model_name, base_url="https://api.stepfun.com/v1"):
         if not base_url:
-            base_url = "https://api.stepfun.com/v1/chat/completions"
+            base_url = "https://api.stepfun.com/v1"
         super().__init__(key, model_name, base_url)