feat(canvas): Agent 审批 - 节点直接生成时自动关闭同节点的待审批任务

用户在画布节点上直接提交生成后，同画布 Agent 对该节点等待中的 generate_media 审批关闭为 superseded_by_node，Agent 带着「用户已手动提交」的结果继续，不重复提交、不扣费。审批卡片识别目标节点正在生成时禁用「同意执行」并提示原因。

web/src/pages/canvas/project.tsx

@@ -2827,7 +2827,7 @@ function InfiniteCanvasPage() {
                             </div>
 
                             <div className={versions.open ? "hidden" : "contents"}>
-                            <CanvasCloudAgentPanel canvasId={projectId} domainProjectId={currentProject?.projectId} nodeCount={nodes.length} selectedNodeIds={Array.from(selectedNodeIds)} references={agentMentionReferences} prefillPrompt={agentPrefillPrompt} open={assistantOpen} onOpen={openAgent} onCollapse={closeAgent} onFocusNode={(nodeId) => {
+                            <CanvasCloudAgentPanel canvasId={projectId} domainProjectId={currentProject?.projectId} canvasNodes={nodes} runningNodeId={runningNodeId} nodeCount={nodes.length} selectedNodeIds={Array.from(selectedNodeIds)} references={agentMentionReferences} prefillPrompt={agentPrefillPrompt} open={assistantOpen} onOpen={openAgent} onCollapse={closeAgent} onFocusNode={(nodeId) => {
                                 const currentNodes = nodesRef.current;
                                 const target = currentNodes.find((node) => node.id === nodeId);
                                 if (!target) { message.info("该节点已删除或尚未同步到画布"); return; }