feat: add history report switcher dropdown in report detail view

webapp/static/js/report.js

@@ -4,11 +4,16 @@ const Report = {
   distChart: null,
   currentDetail: null,
   activeGrouping: null,
+  _switcherLoaded: false,
 
   // 加载并渲染指定运行的完整报告。
   async render(runId) {
     const empty = document.getElementById("report-empty");
     const content = document.getElementById("report-content");
+
+    // 加载历史报告下拉（仅首次）
+    Report._loadSwitcher(runId);
+
     if (!runId) {
       empty.hidden = false;
       content.hidden = true;
@@ -28,6 +33,10 @@ const Report = {
       Report.renderLowest(detail.report);
       Report.renderAdvice(detail.summary, detail.report);
       content.style.opacity = "1";
+
+      // 同步下拉选中项
+      const sel = document.getElementById("report-switcher-select");
+      if (sel) sel.value = runId;
     } catch (err) {
       empty.hidden = false;
       content.hidden = true;
@@ -35,6 +44,55 @@ const Report = {
     }
   },
 
+  // 加载并填充历史报告下拉选择框
+  async _loadSwitcher(currentRunId) {
+    const sel = document.getElementById("report-switcher-select");
+    if (!sel) return;
+
+    // 已加载过就只更新选中值，不重复请求
+    if (Report._switcherLoaded) {
+      if (currentRunId) sel.value = currentRunId;
+      return;
+    }
+
+    try {
+      const data = await API.runs();
+      const runs = data.runs || [];
+      sel.innerHTML = "";
+      if (runs.length === 0) {
+        sel.innerHTML = '<option value="">（无历史运行）</option>';
+        return;
+      }
+      runs.forEach((run) => {
+        const opt = document.createElement("option");
+        opt.value = run.run_id;
+        const timeStr = App.shortTime(run.finished_at);
+        const meanText = run.metric_means
+          ? Object.entries(run.metric_means)
+              .filter(([, v]) => v !== null && v !== undefined)
+              .slice(0, 2)
+              .map(([k, v]) => `${App.shortMetric(k)}=${v.toFixed(2)}`)
+              .join(" ")
+          : "";
+        opt.textContent = `${run.scenario_name || run.run_id}  ${timeStr}${meanText ? "  [" + meanText + "]" : ""}`;
+        sel.appendChild(opt);
+      });
+      Report._switcherLoaded = true;
+      if (currentRunId) sel.value = currentRunId;
+    } catch (_e) {
+      sel.innerHTML = '<option value="">（加载失败）</option>';
+    }
+
+    // 绑定切换事件（只绑一次）
+    sel.addEventListener("change", () => {
+      const rid = sel.value;
+      if (!rid) return;
+      App.currentRunId = rid;
+      App.enableReportNav();
+      Report.render(rid);
+    });
+  },
+
   // 顶部元信息条。
   renderMeta(summary) {
     const el = document.getElementById("report-meta");