fix: 明确退回原因并启用退回操作

src/app/xingbang-workbench/page.tsx

@@ -80,7 +80,7 @@ export default function XingbangWorkspace() {
   }
   async function reportAction(action: string, payload: any = {}) {if (["regenerate", "finalize", "submit"].includes(action) && Object.keys(sectionEdits).length) {setError("请先保存尚未提交的章节修改"); return;} if(action === "submit" && !window.confirm("确认提交正式评审？提交后当前AI预审报告将作为不可覆盖的送审版本保留。")) return; const saved = await act(`${base}/reports/${chosenReport.id}/actions`, {action, revision: chosenReport.revision, payload}, action === "submit" ? "AI预审报告已提交正式评审。" : "报告操作已记录"); if(saved&&action==="submit"){location.href=`/review-pool?submitted=${encodeURIComponent(project.id)}`;return;} if (saved && payload.section_id) setSectionEdits(previous => {const next = {...previous}; delete next[payload.section_id]; return next;});}
   async function reviewDecision(findingId:string|null,decision:string,nodeId?:string,opinion?:string){return act(`${base}/review-decisions`,{finding_id:findingId,node_id:nodeId||null,decision,opinion:opinion??reviewOpinion},findingId||nodeId?"本项评审意见已保存。":decision==="批准"?"评审已批准，正在形成评审报告。":"项目已退回客户经理补件。");}
-  async function completeReview(decision:string){const saved=await reviewDecision(null,decision);if(!saved)return;if(decision==="批准"&&reportSourceRun){const report=await act(`${base}/reports`,{run_id:reportSourceRun.id,template_id:"template.independent-review"},"独立评审报告已生成，请确认后定稿。");if(report)setReportId(report.id);setTab("report");}}
+  async function completeReview(decision:string,opinion?:string){const saved=await reviewDecision(null,decision,undefined,opinion);if(!saved)return;if(decision==="批准"&&reportSourceRun){const report=await act(`${base}/reports`,{run_id:reportSourceRun.id,template_id:"template.independent-review"},"独立评审报告已生成，请确认后定稿。");if(report)setReportId(report.id);setTab("report");}}
   return <div className="ra-app"><AgentNav active="overview" project={project.id} identity={identity}/><main className="xb-overview">
     <button className="xb-back" onClick={back}>← 返回项目列表</button><div className="xb-overview-heading"><div><span className={`xb-role-banner role-${identity?.role}`}>当前身份 · {roleTitle}</span><h1>{project.customer}</h1><p>{project.id} · {project.industry} · {project.stage} · {project.data_domain === "demo" ? "演示数据" : "正式数据"}</p></div><button className="ra-button" onClick={() => open(project.id)}><RefreshCw size={15}/>刷新</button></div>{alerts}
     {isReviewer&&!hasReviewClaim&&<section className="xb-task xb-claim-gate"><div><b>该项目仍在待评审项目池</b><small>领取后将停止等待计时，并记录由你开始办理。</small></div><button className="ra-button primary" disabled={busy} onClick={()=>claimAndOpen(project)}>领取并开始评审</button></section>}