refactor(provider): 简化 Z.AI 提供商实现

本次重构旨在提高 Z.AI 提供商代码的内聚性和可维护性。

主要变更包括：
- 删除了独立的 `zai_transformer.py` 模块，并将其中的辅助函数（如动态请求头生成）直接整合到 `ZAIProvider` 类中。
- 清理了 `models/schemas.py` 和 `providers/base.py` 中一系列未被使用的 Pydantic 模型和数据类。
- 移除了 `core/openai.py` 中不再需要的 `create_chunk` 辅助函数。

这些改动使得 Z.AI 相关逻辑更加集中，减少了模块间的耦合，并清除了冗余代码。

Author: Inblac

app/core/__init__.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
-from app.core import config, zai_transformer, openai
+from app.core import config, openai
 
-__all__ = ["config", "zai_transformer", "openai"]
+__all__ = ["config", "openai"]

app/core/openai.py

@@ -28,23 +28,6 @@ def get_provider_router_instance():
     return provider_router
 
 
-def create_chunk(chat_id: str, model: str, delta: Dict[str, Any], finish_reason: Optional[str] = None) -> Dict[str, Any]:
-    """创建标准的 OpenAI chunk 结构"""
-    return {
-        "choices": [{
-            "delta": delta,
-            "finish_reason": finish_reason,
-            "index": 0,
-            "logprobs": None,
-        }],
-        "created": int(time.time()),
-        "id": chat_id,
-        "model": model,
-        "object": "chat.completion.chunk",
-        "system_fingerprint": "fp_zai_001",
-    }
-
-
 async def handle_non_stream_response(stream_response, request: OpenAIRequest) -> JSONResponse:
     """处理非流式响应"""
     logger.info("📄 开始处理非流式响应")

app/core/zai_transformer.py

@@ -34,32 +34,6 @@ class OpenAIRequest(BaseModel):
     thinking: Optional[Dict[str, Any]] = None
 
 
-class ModelItem(BaseModel):
-    """Model information item"""
-
-    id: str
-    name: str
-    owned_by: str
-
-
-class UpstreamRequest(BaseModel):
-    """Upstream service request model"""
-
-    stream: bool
-    model: str
-    messages: List[Message]
-    params: Dict[str, Any] = {}
-    features: Dict[str, Any] = {}
-    background_tasks: Optional[Dict[str, bool]] = None
-    chat_id: Optional[str] = None
-    id: Optional[str] = None
-    mcp_servers: Optional[List[str]] = None
-    model_item: Optional[Dict[str, Any]] = {}  # Model item dictionary
-    tools: Optional[List[Dict[str, Any]]] = None  # Add tools field for OpenAI compatibility
-    variables: Optional[Dict[str, str]] = None
-    model_config = {"protected_namespaces": ()}
-
-
 class Delta(BaseModel):
     """Stream delta model"""
 
@@ -97,39 +71,6 @@ class OpenAIResponse(BaseModel):
     usage: Optional[Usage] = None
 
 
-class UpstreamError(BaseModel):
-    """Upstream error model"""
-
-    detail: str
-    code: int
-
-
-class UpstreamDataInner(BaseModel):
-    """Inner upstream data model"""
-
-    error: Optional[UpstreamError] = None
-
-
-class UpstreamDataData(BaseModel):
-    """Upstream data content model"""
-
-    delta_content: str = ""
-    edit_content: str = ""
-    phase: str = ""
-    done: bool = False
-    usage: Optional[Usage] = None
-    error: Optional[UpstreamError] = None
-    inner: Optional[UpstreamDataInner] = None
-
-
-class UpstreamData(BaseModel):
-    """Upstream data model"""
-
-    type: str
-    data: UpstreamDataData
-    error: Optional[UpstreamError] = None
-
-
 class Model(BaseModel):
     """Model information for listing"""
 

app/models/schemas.py

@@ -29,16 +29,6 @@ class ProviderConfig:
     extra_config: Optional[Dict[str, Any]] = None
 
 
-@dataclass
-class ProviderResponse:
-    """提供商响应"""
-    success: bool
-    content: str = ""
-    error: Optional[str] = None
-    usage: Optional[Dict[str, int]] = None
-    extra_data: Optional[Dict[str, Any]] = None
-
-
 class BaseProvider(ABC):
     """基础提供商抽象类"""