Add Dify integration and enhance workflow node specifications

- Introduce new fields `dify_api_url` and `dify_api_key` in `AssistantConfig` for Dify API integration.
- Update `requirements.txt` to include `dify-client-python` for Dify SDK support.
- Modify `config_resolver` to handle Dify connection information.
- Add a new `globalNode` type in workflow specifications to provide unified settings across workflows.
- Enhance node specifications with additional constraints and default values for better configuration management.
- Update frontend components to support the new `globalNode` type and its properties, improving workflow editor functionality.

frontend/src/components/workflow/specs.ts

@@ -11,7 +11,11 @@ import { Circle, type LucideIcon } from "lucide-react";
 
 import type { NodeSpecDto } from "@/lib/api";
 
-export type WorkflowNodeType = "startCall" | "agentNode" | "endCall";
+export type WorkflowNodeType =
+  | "startCall"
+  | "agentNode"
+  | "endCall"
+  | "globalNode";
 
 export type WorkflowNodeData = {
   /** 节点显示名 */
@@ -22,6 +26,8 @@ export type WorkflowNodeData = {
   prompt?: string;
   /** 允许打断(仅 agentNode) */
   allowInterrupt?: boolean;
+  /** 是否合并全局节点提示词(start/agent 默认开启,end 默认关闭) */
+  addGlobalPrompt?: boolean;
   [key: string]: unknown;
 };
 
@@ -30,6 +36,7 @@ export type FieldSpec = {
   label: string;
   type: "text" | "textarea" | "switch";
   required?: boolean;
+  default?: unknown;
 };
 
 /** 解析后的运行期节点规格(DTO + 解析出的 React 图标 + 派生句柄) */
@@ -44,6 +51,14 @@ export type RuntimeNodeSpec = {
   hasTarget: boolean;
   /** 出边句柄(结束节点没有) */
   hasSource: boolean;
+  constraints: {
+    minIncoming?: number;
+    maxIncoming?: number;
+    minOutgoing?: number;
+    maxOutgoing?: number;
+    minInstances?: number;
+    maxInstances?: number;
+  };
   fields: FieldSpec[];
 };
 
@@ -77,11 +92,13 @@ export function toRuntimeSpec(dto: NodeSpecDto): RuntimeNodeSpec {
     addable: dto.addable,
     hasTarget: dto.constraints.maxIncoming !== 0,
     hasSource: dto.constraints.maxOutgoing !== 0,
+    constraints: dto.constraints,
     fields: dto.fields.map((f) => ({
       key: f.key,
       label: f.label,
       type: f.type,
       required: f.required,
+      default: f.default,
     })),
   };
 }
@@ -104,27 +121,52 @@ export type WorkflowGraph = {
   viewport?: { x: number; y: number; zoom: number };
 };
 
-/** 新建工作流的默认图:开始 → 智能体 → 结束 */
+/** 新建工作流的默认图:全局规则 + 开始 → 智能体 → 结束 */
 export function defaultGraph(): WorkflowGraph {
   return {
     nodes: [
       {
         id: "start",
         type: "startCall",
-        position: { x: 80, y: 160 },
-        data: { name: "开始", greeting: "你好,我是 AI 视频助手,有什么可以帮你?" },
+        position: { x: 100, y: 120 },
+        data: {
+          name: "开始",
+          greeting: "你好,我是 AI 视频助手,有什么可以帮你?",
+          prompt: "了解用户的需求,并在信息明确后进入下一节点。",
+          allowInterrupt: true,
+          addGlobalPrompt: true,
+        },
       },
       {
         id: "agent-1",
         type: "agentNode",
-        position: { x: 400, y: 160 },
-        data: { name: "智能体节点", prompt: "", allowInterrupt: true },
+        position: { x: 420, y: 120 },
+        data: {
+          name: "智能体节点",
+          prompt: "根据用户需求提供清晰、准确的帮助。",
+          allowInterrupt: true,
+          addGlobalPrompt: true,
+        },
       },
       {
         id: "end",
         type: "endCall",
-        position: { x: 720, y: 160 },
-        data: { name: "结束", prompt: "感谢你的来电,再见!" },
+        position: { x: 740, y: 120 },
+        data: {
+          name: "结束",
+          prompt: "总结已经完成的事项,礼貌道别并结束通话。",
+          addGlobalPrompt: false,
+        },
+      },
+      {
+        id: "global",
+        type: "globalNode",
+        position: { x: 100, y: 400 },
+        data: {
+          name: "全局设定",
+          prompt:
+            "你是一个友好、专业的语音助手。请使用简短、自然、适合口语表达的句子。",
+        },
       },
     ],
     edges: [