feat(workflow): support context injection in LLM node

api/app/core/workflow/nodes/llm/config.py

@@ -1,5 +1,7 @@
 """LLM 节点配置"""
 
+from typing import Any
+
 from pydantic import BaseModel, Field, field_validator
 
 from app.core.workflow.nodes.base_config import BaseNodeConfig, VariableDefinition, VariableType
@@ -41,6 +43,11 @@ class LLMNodeConfig(BaseNodeConfig):
         description="模型配置 ID"
     )
 
+    context: Any = Field(
+        default="",
+        description="上下文"
+    )
+
     # 简单模式
     prompt: str | None = Field(
         default=None,