feat(workflow): add node duplication

frontend/src/components/workflow/GenericNode.tsx

@@ -2,11 +2,11 @@
 
 /**
  * 通用节点渲染器。所有节点类型共用一个组件,规格来自 NodeSpecsContext
- * (后端 /api/node-types)。悬停/选中时在右上角显示「编辑 / 删除」按钮。
+ * (后端 /api/node-types)。悬停/选中时在右上角显示「编辑 / 复制 / 删除」按钮。
  */
 
 import { Handle, Position, type NodeProps } from "@xyflow/react";
-import { MessageSquareText, Pencil, Trash2 } from "lucide-react";
+import { Copy, MessageSquareText, Pencil, Trash2 } from "lucide-react";
 import { useContext } from "react";
 
 import { cn } from "@/lib/utils";
@@ -130,6 +130,7 @@ export function GenericNode({ id, type, data, selected }: NodeProps) {
         <button
           type="button"
           title="编辑节点"
+          aria-label="编辑节点"
           className="flex h-7 w-7 items-center justify-center rounded-full border border-hairline bg-card text-muted-foreground shadow-sm transition-colors hover:text-foreground"
           onClick={(e) => {
             e.stopPropagation();
@@ -139,9 +140,23 @@ export function GenericNode({ id, type, data, selected }: NodeProps) {
           <Pencil size={13} />
         </button>
         {type !== "start" && (
+          <>
+            <button
+              type="button"
+              title="复制节点"
+              aria-label="复制节点"
+              className="flex h-7 w-7 items-center justify-center rounded-full border border-hairline bg-card text-muted-foreground shadow-sm transition-colors hover:text-foreground"
+              onClick={(e) => {
+                e.stopPropagation();
+                actions.duplicate(id);
+              }}
+            >
+              <Copy size={13} />
+            </button>
             <button
               type="button"
               title="删除节点"
+              aria-label="删除节点"
               className="flex h-7 w-7 items-center justify-center rounded-full border border-hairline bg-card text-muted-foreground shadow-sm transition-colors hover:text-destructive"
               onClick={(e) => {
                 e.stopPropagation();
@@ -150,6 +165,7 @@ export function GenericNode({ id, type, data, selected }: NodeProps) {
             >
               <Trash2 size={13} />
             </button>
+          </>
         )}
       </div>
 

frontend/src/components/workflow/WorkflowCanvas.tsx

@@ -328,6 +328,50 @@ export function WorkflowCanvas({
     [editingNodeId, nodes, onEditingNodeIdChange, setNodes, setEdges],
   );
 
+  const duplicateNode = useCallback(
+    (id: string) => {
+      const source = nodes.find((node) => node.id === id);
+      if (!source || source.type === "start") return;
+
+      const spec = specsByType[source.type as string];
+      if (!spec) return;
+      const limit = spec.constraints.maxInstances;
+      if (
+        limit !== undefined &&
+        nodes.filter((node) => node.type === source.type).length >= limit
+      ) {
+        return;
+      }
+
+      nodeSeq += 1;
+      const duplicateId = `${source.type}-${Date.now()}-${nodeSeq}`;
+      const sourceData = source.data as WorkflowNodeData;
+      const duplicateData = structuredClone(sourceData);
+      duplicateData.name = `${sourceData.name || spec.displayName}（副本）`;
+
+      setNodes((currentNodes) => [
+        ...currentNodes.map((node) => ({ ...node, selected: false })),
+        {
+          id: duplicateId,
+          type: source.type,
+          position: {
+            x: source.position.x + 40,
+            y: source.position.y + 40,
+          },
+          data: duplicateData,
+          selected: true,
+        },
+      ]);
+      onEditingNodeIdChange(null);
+    },
+    [
+      nodes,
+      onEditingNodeIdChange,
+      setNodes,
+      specsByType,
+    ],
+  );
+
   const handleNodesChange = useCallback(
     (changes: NodeChange[]) => {
       const startIds = new Set(
@@ -431,10 +475,12 @@ export function WorkflowCanvas({
         onEditingEdgeIdChange(null);
         onEditingNodeIdChange(id);
       },
+      duplicate: duplicateNode,
       remove: deleteNode,
     }),
     [
       deleteNode,
+      duplicateNode,
       onDebugOpenChange,
       onEditingEdgeIdChange,
       onEditingNodeIdChange,

frontend/src/components/workflow/context.ts

@@ -2,7 +2,7 @@
 
 /**
  * 画布内共享上下文。GenericNode / ConditionEdge 由 ReactFlow 渲染,拿不到外层
- * 回调,统一通过这些 context 取节点规格与编辑/删除动作。
+ * 回调,统一通过这些 context 取节点规格与编辑/复制/删除动作。
  */
 
 import { createContext } from "react";
@@ -17,9 +17,14 @@ export type ElementActions = {
   remove: (id: string) => void;
 };
 
-const noop: ElementActions = { edit: () => {}, remove: () => {} };
+export type NodeActions = ElementActions & {
+  duplicate: (id: string) => void;
+};
 
-export const NodeActionContext = createContext<ElementActions>(noop);
+const noop: ElementActions = { edit: () => {}, remove: () => {} };
+const noopNodeActions: NodeActions = { ...noop, duplicate: () => {} };
+
+export const NodeActionContext = createContext<NodeActions>(noopNodeActions);
 export const EdgeActionContext = createContext<ElementActions>(noop);
 
 /** 调试通话中当前激活的节点 id(画布据此高亮),无激活为 null。 */