feat: Phase 4 — Experiment 自动归档 + 异步 Job（状态机 / SSE / 一键复跑）

- 数据表：job / experiment（spec/result JSON 存档、code_version），Alembic 迁移 53113c80257f
- Job：queued→running→(success|failed) 状态机，BackgroundTasks 本地执行 + 失败兜底标记；结果与 Experiment 关联
- Experiment：每次研究成功自动归档（含 git commit 与收益摘要），支持一键复跑（同 spec 重建 Job）
- API：POST /api/jobs、GET /api/jobs/{id}（内嵌结果）、SSE /api/jobs/{id}/events、/api/experiments 列表/详情/rerun
- 前端：新增「实验」页（列表 / 详情 / 复跑 + Job 轮询）；导航更新
- 端到端验证：真实 20 股 job 提交→后台执行→success→EXP 归档（-12.41%）；executor 成功/失败路径单测
- 测试 73 passed（新增 5 项 Job/Experiment）/ ruff clean / 前端 tsc + build 通过

frontend/web/app/experiments/page.tsx

@@ -0,0 +1,158 @@
+"use client";
+
+import { useEffect, useState } from "react";
+import { apiGet, apiPost } from "@/lib/api";
+import type { BacktestResult } from "@/lib/types";
+
+interface ExperimentMeta {
+  id: string;
+  kind: string;
+  factors: string[];
+  period?: [string, string] | null;
+  rebalance?: string;
+  top_n?: number | null;
+  summary_text?: string | null;
+  code_version?: string | null;
+  created_at?: string;
+}
+
+interface ExperimentDetail extends ExperimentMeta {
+  spec: { universe?: Record<string, unknown> };
+  result: BacktestResult | null;
+}
+
+export default function ExperimentsPage() {
+  const [exps, setExps] = useState<ExperimentMeta[]>([]);
+  const [detail, setDetail] = useState<ExperimentDetail | null>(null);
+  const [jobId, setJobId] = useState("");
+  const [jobStatus, setJobStatus] = useState("");
+  const [error, setError] = useState("");
+
+  function load() {
+    apiGet<ExperimentMeta[]>("/experiments")
+      .then(setExps)
+      .catch((e: Error) => setError(e.message));
+  }
+
+  useEffect(load, []);
+
+  function open(id: string) {
+    apiGet<ExperimentDetail>(`/experiments/${id}`)
+      .then(setDetail)
+      .catch((e: Error) => setError(e.message));
+  }
+
+  function rerun(exp: ExperimentMeta) {
+    setError("");
+    setJobId("");
+    setJobStatus("submitting");
+    apiPost<{ job_id: string; status: string }>(`/experiments/${exp.id}/rerun`, {})
+      .then((r) => {
+        setJobId(r.job_id);
+        setJobStatus(r.status);
+        poll(r.job_id);
+      })
+      .catch((e: Error) => setError(e.message));
+  }
+
+  function poll(id: string) {
+    let tries = 0;
+    const timer = window.setInterval(() => {
+      tries += 1;
+      apiGet<{ status: string }>(`/jobs/${id}`)
+        .then((j) => {
+          setJobStatus(j.status);
+          if (j.status === "success" || j.status === "failed" || tries > 60) {
+            window.clearInterval(timer);
+            load();
+          }
+        })
+        .catch(() => window.clearInterval(timer));
+    }, 1000);
+  }
+
+  const s = detail?.result?.summary;
+
+  return (
+    <>
+      <h1>实验归档（Experiment · 可复现）</h1>
+      {error && <div className="error">{error}</div>}
+      {jobId && (
+        <div className="card">
+          复跑 Job <b>{jobId}</b> → 状态：<b>{jobStatus}</b>
+        </div>
+      )}
+      <div className="card">
+        <table>
+          <thead>
+            <tr>
+              <th>ID</th>
+              <th>类型</th>
+              <th>因子</th>
+              <th>区间</th>
+              <th>摘要</th>
+              <th>代码版本</th>
+              <th></th>
+            </tr>
+          </thead>
+          <tbody>
+            {exps.map((e) => (
+              <tr key={e.id}>
+                <td>{e.id}</td>
+                <td>{e.kind}</td>
+                <td>{e.factors.join(", ")}</td>
+                <td>
+                  {e.period ? `${e.period[0]} ~ ${e.period[1]}` : "—"}
+                </td>
+                <td>{e.summary_text ?? "—"}</td>
+                <td>{e.code_version ?? "—"}</td>
+                <td>
+                  <button onClick={() => open(e.id)}>详情</button>
+                  <button className="primary" onClick={() => rerun(e)}>
+                    复跑
+                  </button>
+                </td>
+              </tr>
+            ))}
+            {exps.length === 0 && (
+              <tr>
+                <td colSpan={7} className="muted">
+                  暂无实验。先在「回测」或「因子研究」中运行一次，即会自动归档。
+                </td>
+              </tr>
+            )}
+          </tbody>
+        </table>
+      </div>
+
+      {detail && s && (
+        <div className="card">
+          <h2>
+            {detail.id} · {detail.factors.join(", ")} · {detail.period?.[0]}~{detail.period?.[1]}
+          </h2>
+          <div className="stat-grid">
+            <div className="stat">
+              <div className="label">总收益</div>
+              <div className="value">{s.total_return_pct.toFixed(2)}%</div>
+            </div>
+            <div className="stat">
+              <div className="label">年化</div>
+              <div className="value">{s.annual_return_pct.toFixed(2)}%</div>
+            </div>
+            <div className="stat">
+              <div className="label">Sharpe</div>
+              <div className="value">{s.sharpe.toFixed(2)}</div>
+            </div>
+            <div className="stat">
+              <div className="label">最大回撤</div>
+              <div className="value bad">{s.max_drawdown_pct.toFixed(2)}%</div>
+            </div>
+          </div>
+          <div className="muted" style={{ marginTop: 8 }}>
+            spec（可复现输入）：{JSON.stringify(detail.spec).slice(0, 400)}…
+          </div>
+        </div>
+      )}
+    </>
+  );
+}

frontend/web/app/layout.tsx

@@ -17,6 +17,7 @@ export default function RootLayout({ children }: { children: React.ReactNode })
           <Link href="/stocks">股票池</Link>
           <Link href="/factors">因子研究</Link>
           <Link href="/backtest">回测</Link>
+          <Link href="/experiments">实验</Link>
         </nav>
         <main>{children}</main>
       </body>