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.

frontend/src/components/workflow/ConditionEdge.tsx

@@ -1,14 +1,13 @@
 "use client";
 
 /**
- * 条件边。边携带 condition(自然语言条件,LLM 据此决定是否走这条路径)与
- * label(日志里识别该路径的短标签)。悬停/选中时在标签旁显示「编辑 / 删除」按钮。
+ * Workflow v3 edge: LLM judgement, variable expression, or deterministic default.
  */
 
 import {
   BaseEdge,
   EdgeLabelRenderer,
-  getSmoothStepPath,
+  getBezierPath,
   type EdgeProps,
   useReactFlow,
 } from "@xyflow/react";
@@ -36,20 +35,22 @@ export function ConditionEdge({
   // 点击标签:只选中这条边(露出编辑/删除按钮),不直接进入编辑。
   const selectThisEdge = () =>
     setEdges((eds) => eds.map((e) => ({ ...e, selected: e.id === id })));
-  const [path, labelX, labelY] = getSmoothStepPath({
+  const [path, labelX, labelY] = getBezierPath({
     sourceX,
     sourceY,
     sourcePosition,
     targetX,
     targetY,
     targetPosition,
-    borderRadius: 8,
-    offset: 20,
+    curvature: 0.28,
   });
 
-  const label = ((data?.label as string) || (data?.condition as string) || "")
-    .toString()
-    .trim();
+  const mode = (data?.mode as string) || "always";
+  const label = (
+    (data?.label as string) ||
+    (mode === "llm" ? (data?.condition as string) : "") ||
+    (mode === "expression" ? "变量表达式" : "默认路径")
+  ).toString().trim();
   const expanded = hovered || selected;
 
   return (