Add workflow support and enhance runtime configuration in models and services

- Introduce RuntimeModelResource and RuntimeKnowledgeBase classes to manage workflow resources.
- Update AssistantConfig to include workflow_model_resources and workflow_knowledge_bases for better integration.
- Refactor validation and processing logic in routes and services to accommodate workflow types.
- Implement dynamic variable support for workflow assistants and enhance graph normalization.
- Add ToolExecutor for reusable tool execution across different assistant types.
- Update various services to ensure compatibility with new workflow features and improve error handling.

backend/routes/knowledge_bases.py

@@ -15,6 +15,7 @@ from schemas import (
 )
 from services.auth import require_admin
 from services.knowledge import create_document, delete_storage_object, process_document, search
+from services.node_specs import graph_references
 import settings
 from sqlalchemy import select
 from sqlalchemy.exc import IntegrityError
@@ -123,6 +124,14 @@ async def delete_knowledge_base(
     )).scalar_one_or_none()
     if referenced:
         raise HTTPException(409, "知识库正被助手引用,无法删除")
+    workflows = (
+        await session.execute(select(Assistant).where(Assistant.type == "workflow"))
+    ).scalars().all()
+    if any(
+        kb_id in graph_references(assistant.graph or {})["knowledge_bases"]
+        for assistant in workflows
+    ):
+        raise HTTPException(409, "知识库正被 Workflow 节点引用,无法删除")
     documents = (await session.execute(
         select(KnowledgeDocument).where(KnowledgeDocument.knowledge_base_id == kb_id)
     )).scalars().all()