feat: implement Polymarket read-only data service and add scan terminal dashboard components

frontend/components/dashboard/Dashboard.module.css

@@ -9251,35 +9251,25 @@
   border-bottom: 1px solid rgba(118, 146, 188, 0.1);
 }
 
-.root :global(.scan-topbar-tabs) {
+.root :global(.scan-topbar-title) {
   display: flex;
-  gap: 28px;
+  flex-direction: column;
+  gap: 6px;
+  min-width: 0;
 }
 
-.root :global(.scan-topbar-tab) {
-  position: relative;
-  border: none;
-  background: transparent;
-  color: #b4c8e2;
-  font-size: 17px;
-  font-weight: 700;
-  cursor: pointer;
+.root :global(.scan-topbar-title strong) {
+  margin: 0;
+  font-size: 28px;
+  line-height: 1.08;
+  letter-spacing: -0.04em;
+  color: #f3f8ff;
 }
 
-.root :global(.scan-topbar-tab.active) {
-  color: #fff;
-}
-
-.root :global(.scan-topbar-tab.active::after) {
-  content: "";
-  position: absolute;
-  left: 0;
-  right: 0;
-  bottom: -18px;
-  height: 3px;
-  border-radius: 999px;
-  background: #3f8cff;
-  box-shadow: 0 0 14px rgba(63, 140, 255, 0.4);
+.root :global(.scan-topbar-title span) {
+  color: #8fa4c3;
+  font-size: 14px;
+  line-height: 1.5;
 }
 
 .root :global(.scan-topbar-actions) {
@@ -9329,8 +9319,6 @@
 .root :global(.scan-ghost-button),
 .root :global(.scan-cta-ghost),
 .root :global(.scan-theme-button),
-.root :global(.scan-sort-pill),
-.root :global(.scan-icon-pill),
 .root :global(.scan-detail-action-button),
 .root :global(.scan-detail-icon-button),
 .root :global(.scan-view-all-button) {
@@ -9386,21 +9374,8 @@
   animation: spin 1s linear infinite;
 }
 
-.root :global(.scan-hero h1) {
-  margin: 0;
-  font-size: 44px;
-  line-height: 1.08;
-  letter-spacing: -0.04em;
-}
-
-.root :global(.scan-hero p) {
-  margin: 10px 0 0;
-  color: #8fa4c3;
-  font-size: 16px;
-}
-
 .root :global(.scan-kpi-bar) {
-  grid-template-columns: repeat(5, minmax(0, 1fr));
+  grid-template-columns: repeat(4, minmax(0, 1fr));
   gap: 14px;
 }
 
@@ -9425,6 +9400,10 @@
   color: #17d98b;
 }
 
+.root :global(.scan-kpi-card.cyan .scan-kpi-label) {
+  color: #37d6ff;
+}
+
 .root :global(.scan-kpi-card.purple .scan-kpi-label) {
   color: #a35cff;
 }
@@ -9433,6 +9412,14 @@
   color: #49a3ff;
 }
 
+.root :global(.scan-kpi-card.red .scan-kpi-label) {
+  color: #ff647c;
+}
+
+.root :global(.scan-kpi-card.amber .scan-kpi-label) {
+  color: #ffb84f;
+}
+
 .root :global(.scan-kpi-card.orange .scan-kpi-label) {
   color: #ffb020;
 }
@@ -9487,20 +9474,37 @@
   color: #fff;
 }
 
-.root :global(.scan-list-controls) {
+.root :global(.scan-list-status) {
   display: flex;
   gap: 10px;
+  align-items: center;
 }
 
-.root :global(.scan-sort-pill) {
-  min-width: 188px;
-  padding: 12px 14px;
+.root :global(.scan-status-chip) {
+  display: inline-flex;
+  align-items: center;
+  gap: 8px;
+  height: 34px;
+  padding: 0 12px;
+  border-radius: 999px;
+  border: 1px solid rgba(98, 126, 167, 0.22);
+  background: rgba(10, 22, 38, 0.92);
+  color: #c4d4e9;
+  font-size: 12px;
+  font-weight: 800;
+  letter-spacing: 0.02em;
 }
 
-.root :global(.scan-icon-pill) {
-  width: 48px;
-  display: grid;
-  place-items: center;
+.root :global(.scan-status-chip.live) {
+  border-color: rgba(55, 214, 255, 0.28);
+  background: rgba(55, 214, 255, 0.1);
+  color: #71e6ff;
+}
+
+.root :global(.scan-status-chip.stale) {
+  border-color: rgba(255, 184, 79, 0.24);
+  background: rgba(255, 184, 79, 0.1);
+  color: #ffc765;
 }
 
 .root :global(.scan-table-shell) {
@@ -9518,6 +9522,27 @@
   min-height: 340px;
 }
 
+.root :global(.scan-table-banner) {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 8px;
+  align-items: center;
+  padding: 12px 16px;
+  border-bottom: 1px solid rgba(95, 124, 168, 0.12);
+  background: linear-gradient(180deg, rgba(255, 184, 79, 0.08), rgba(255, 184, 79, 0.03));
+}
+
+.root :global(.scan-table-banner strong) {
+  font-size: 13px;
+  font-weight: 800;
+  color: #ffd27f;
+}
+
+.root :global(.scan-table-banner span) {
+  font-size: 13px;
+  color: #c7d4e7;
+}
+
 .root :global(.scan-table-header) {
   display: grid;
   grid-template-columns: 46px minmax(180px, 1.08fr) minmax(132px, 0.72fr) minmax(220px, 1.08fr) minmax(150px, 0.82fr) 92px 82px;

frontend/components/dashboard/OpportunityTable.tsx

@@ -153,8 +153,8 @@ function ProbabilityPreview({
     });
   }
 
-  const modelLabel = locale === "en-US" ? "M" : "模";
-  const marketLabel = locale === "en-US" ? "P" : "市";
+  const modelLabel = "EMOS";
+  const marketLabel = locale === "en-US" ? "Market" : "市场";
 
   return (
     <div className="scan-distribution-preview">
@@ -202,28 +202,53 @@ function ScoreRing({ score }: { score?: number | null }) {
 
 export const OpportunityTable = React.memo(function OpportunityTable({
   rows,
+  status,
+  stale,
+  staleReason,
+  loading,
   selectedRowId,
   onSelectRow,
 }: {
   rows: ScanOpportunityRow[];
+  status?: string | null;
+  stale?: boolean;
+  staleReason?: string | null;
+  loading?: boolean;
   selectedRowId?: string | null;
   onSelectRow?: (row: ScanOpportunityRow) => void;
 }) {
   const { locale } = useI18n();
   const isEn = locale === "en-US";
+  const hasRows = rows.length > 0;
 
-  if (!rows.length) {
+  if (!hasRows) {
+    const title =
+      loading
+        ? isEn
+          ? "Scanning markets"
+          : "正在扫描市场"
+        : status === "failed"
+          ? isEn
+            ? "Scan failed"
+            : "扫描失败"
+          : isEn
+            ? "No tradable market right now"
+            : "当前暂无可交易市场";
+    const copy =
+      loading
+        ? isEn
+          ? "Waiting for the latest market snapshot. Existing data will stay on screen when available."
+          : "正在等待最新市场快照；如果有旧数据，会继续保留在页面上。"
+        : status === "failed"
+          ? staleReason || (isEn ? "No valid market snapshot is available." : "当前没有可用的市场快照。")
+          : isEn
+            ? "The current snapshot does not contain a tradable main signal."
+            : "当前快照里还没有可交易的主信号。";
     return (
       <div className="scan-table-shell empty">
         <div className="scan-empty-state">
-          <div className="scan-empty-title">
-            {isEn ? "No main signal right now" : "当前无主信号"}
-          </div>
-          <div className="scan-empty-copy">
-            {isEn
-              ? "No row passed the price, spread, liquidity, and edge thresholds."
-              : "当前没有机会同时满足价格、点差、流动性和 edge 过滤。"}
-          </div>
+          <div className="scan-empty-title">{title}</div>
+          <div className="scan-empty-copy">{copy}</div>
         </div>
       </div>
     );
@@ -231,12 +256,18 @@ export const OpportunityTable = React.memo(function OpportunityTable({
 
   return (
     <div className="scan-table-shell">
+      {stale ? (
+        <div className="scan-table-banner">
+          <strong>{isEn ? "Showing delayed snapshot" : "当前显示延迟快照"}</strong>
+          <span>{staleReason || (isEn ? "Latest refresh failed, fallback to the last successful scan." : "最新刷新失败，已回退到上次成功扫描结果。")}</span>
+        </div>
+      ) : null}
       <div className="scan-table-header">
         <span />
         <span>{isEn ? "City / Market" : "城市 / 市场"}</span>
         <span>{isEn ? "Local Time / Phase" : "当前时间 / 阶段"}</span>
-        <span>{isEn ? "EMOS vs Market" : "EMOS 分布 vs 市场分布"}</span>
-        <span>{isEn ? "Best Opportunity" : "最佳机会"}</span>
+        <span>{isEn ? "EMOS / Market" : "EMOS / 市场"}</span>
+        <span>{isEn ? "Quote / Model" : "买价 / 模型"}</span>
         <span>{isEn ? "Edge" : "边际优势"}</span>
         <span>{isEn ? "Score" : "综合得分"}</span>
       </div>
@@ -292,8 +323,8 @@ export const OpportunityTable = React.memo(function OpportunityTable({
                   {formatAction(row, locale, tempSymbol)}
                   </div>
                 <div className="scan-trade-sub">
-                  {formatPercent(row.ask != null ? row.ask * 100 : null)} →{" "}
-                  {formatPercent(row.model_probability != null ? row.model_probability * 100 : null)}
+                  {isEn ? "Buy" : "买价"} {row.ask != null ? `${Math.round(row.ask * 100)}¢` : "--"} ·{" "}
+                  EMOS {formatPercent(row.model_probability != null ? row.model_probability * 100 : null)}
                 </div>
                 <div className="scan-trade-note">
                   {normalizeTemperatureLabel(row.target_label, tempSymbol) ||

frontend/components/dashboard/ScanKPIBar.tsx

@@ -2,56 +2,99 @@
 
 import React from "react";
 import { useI18n } from "@/hooks/useI18n";
-import type { ScanTerminalResponse } from "@/lib/dashboard-types";
+import type { ScanOpportunityRow, ScanTerminalResponse } from "@/lib/dashboard-types";
 
-type KPIData = ScanTerminalResponse["summary"];
-
-function formatVolume(value: number): string {
-  if (value >= 1_000_000) return `$${(value / 1_000_000).toFixed(1)}M`;
-  if (value >= 1_000) return `$${(value / 1_000).toFixed(0)}K`;
-  return `$${value.toFixed(0)}`;
+function formatPercent(value?: number | null, signed = false): string {
+  if (value == null || Number.isNaN(Number(value))) return "--";
+  const numeric = Number(value);
+  return `${signed && numeric >= 0 ? "+" : ""}${numeric.toFixed(1)}%`;
 }
 
-export function ScanKPIBar({ data }: { data: KPIData }) {
+function countByRisk(rows: ScanOpportunityRow[]) {
+  return rows.reduce(
+    (acc, row) => {
+      const risk = String(row.risk_level || "").toLowerCase();
+      if (risk.includes("high")) acc.high += 1;
+      else if (risk.includes("medium")) acc.medium += 1;
+      else acc.low += 1;
+      return acc;
+    },
+    { high: 0, medium: 0, low: 0 },
+  );
+}
+
+export function ScanKPIBar({
+  response,
+  rows,
+  totalCities,
+  loading,
+}: {
+  response: ScanTerminalResponse | null;
+  rows: ScanOpportunityRow[];
+  totalCities: number;
+  loading: boolean;
+}) {
   const { locale } = useI18n();
   const isEn = locale === "en-US";
+  const summary = response?.summary;
+  const riskCounts = countByRisk(rows);
+  const tradableRows = rows.filter((row) => row.tradable && !row.closed);
+  const liveRows = rows.filter((row) => row.active || row.accepting_orders);
+  const bestRow = rows[0] || null;
+  const statusLabel =
+    loading && !response
+      ? isEn
+        ? "Scanning"
+        : "扫描中"
+      : response?.status === "stale"
+        ? isEn
+          ? "Stale"
+          : "旧数据"
+        : response?.status === "failed"
+          ? isEn
+            ? "Failed"
+            : "失败"
+          : isEn
+            ? "Live"
+            : "最新";
 
   const cards = [
     {
-      label: isEn ? "Recommended" : "推荐机会",
-      value: String(data.recommended_count),
-      note: `${isEn ? "Visible" : "当前展示"} ${data.visible_count}`,
-      tone: "green",
+      label: isEn ? "Scan Status" : "扫描状态",
+      value: `${rows.length}/${totalCities || 0}`,
+      note:
+        loading && response
+          ? isEn
+            ? "Refreshing latest snapshot"
+            : "正在刷新最新快照"
+          : response?.status === "stale"
+            ? response.stale_reason || (isEn ? "Using last good snapshot" : "正在使用上次成功快照")
+            : response?.status === "failed"
+              ? response.stale_reason || (isEn ? "No valid snapshot" : "当前没有可用快照")
+              : `${isEn ? "Snapshot" : "快照"} · ${statusLabel}`,
+      tone: response?.status === "failed" ? "red" : response?.status === "stale" ? "amber" : "cyan",
     },
     {
-      label: isEn ? "Avg Edge" : "平均边际优势",
-      value:
-        data.avg_edge_percent != null
-          ? `+${data.avg_edge_percent.toFixed(1)}%`
-          : "--",
-      note: `${isEn ? "Candidates" : "候选总数"} ${data.candidate_total}`,
-      tone: "purple",
-    },
-    {
-      label: isEn ? "Avg Confidence" : "平均主信号置信度",
-      value:
-        data.avg_primary_confidence != null
-          ? `+${data.avg_primary_confidence.toFixed(1)}%`
-          : "--",
-      note: isEn ? "Main signal score" : "主信号评分",
+      label: isEn ? "Book Status" : "盘口状态",
+      value: `${liveRows.length}`,
+      note: `${isEn ? "Tradable" : "可交易"} ${tradableRows.length} · ${isEn ? "No edge" : "无机会"} ${Math.max(0, rows.length - tradableRows.length)}`,
       tone: "blue",
     },
     {
-      label: isEn ? "Tradable Markets" : "可交易市场",
-      value: String(data.tradable_market_count),
-      note: `${isEn ? "Filtered" : "过滤后"} / ${data.candidate_total || 0}`,
-      tone: "orange",
+      label: isEn ? "Opportunity Quality" : "机会质量",
+      value: formatPercent(summary?.avg_edge_percent, true),
+      note: bestRow
+        ? `${isEn ? "Best" : "最佳"} ${bestRow.city_display_name || bestRow.display_name || bestRow.city} · ${formatPercent(bestRow.edge_percent, true)}`
+        : isEn
+          ? "No active market now"
+          : "当前没有活跃市场",
+      tone: "green",
     },
     {
-      label: isEn ? "Total Volume" : "总成交量",
-      value: formatVolume(data.total_volume),
-      note: isEn ? "Past 24 hours" : "过去 24 小时",
-      tone: "neutral",
+      label: isEn ? "Risk Layers" : "风险层",
+      value: `${riskCounts.high} / ${riskCounts.medium} / ${riskCounts.low}`,
+      note: `${isEn ? "High / Med / Low" : "高 / 中 / 低"}`,
+      tone: "purple",
     },
   ];
 

frontend/components/dashboard/ScanTerminalDashboard.tsx

@@ -3,8 +3,6 @@
 import clsx from "clsx";
 import Link from "next/link";
 import {
-  Bell,
-  Menu,
   RefreshCw,
   Moon,
   Sun,
@@ -64,26 +62,8 @@ const DEFAULT_FILTERS: FilterState = {
   limit: 28,
 };
 
-const NAV_ITEMS = [
-  { zh: "扫描台", en: "Terminal" },
-  { zh: "市场", en: "Markets" },
-  { zh: "分析", en: "Analysis" },
-  { zh: "组合", en: "Portfolio" },
-  { zh: "监控", en: "Monitor" },
-  { zh: "设置", en: "Settings" },
-];
-
-type TopSection = "terminal" | "markets" | "analysis" | "portfolio" | "monitor" | "settings";
 type ContentView = "list" | "map" | "calendar";
 type ThemeMode = "dark" | "light";
-const TOP_SECTION_ORDER: TopSection[] = [
-  "terminal",
-  "markets",
-  "analysis",
-  "portfolio",
-  "monitor",
-  "settings",
-];
 
 function formatPercent(value?: number | null, signed = false) {
   if (value == null || Number.isNaN(Number(value))) return "--";
@@ -379,9 +359,6 @@ function DetailPanel({
             {loading ? ` · ${isEn ? "loading" : "载入中"}` : ""}
           </div>
         </div>
-        <button type="button" className="scan-detail-action-button">
-          {isEn ? "Add Watch" : "添加自选"}
-        </button>
       </div>
 
       <div className="scan-detail-primary-actions">
@@ -443,18 +420,9 @@ function DetailPanel({
             </strong>
           </div>
           <div className="scan-kv">
-            <span>{isEn ? "Window Left" : "剩余有效时间"}</span>
+            <span>{isEn ? "Time To Peak" : "距离预测峰值"}</span>
             <strong>{formatRemainingWindow(displayRow.remaining_window_minutes, locale)}</strong>
           </div>
-          <div className="scan-kv">
-            <span>{isEn ? "Bias" : "分布偏移"}</span>
-            <strong>
-              {displayRow.distribution_bias_direction || "--"} ·{" "}
-              {displayRow.distribution_bias_score != null
-                ? displayRow.distribution_bias_score.toFixed(0)
-                : "--"}
-            </strong>
-          </div>
           <div className="scan-kv">
             <span>{isEn ? "Airport" : "机场锚点"}</span>
             <strong>{localizedAirport || "--"}</strong>
@@ -521,38 +489,35 @@ function DetailPanel({
       </section>
 
       <section className="scan-detail-section">
-        <div className="scan-trade-cards">
-          <div className="scan-trade-card buy">
-            <div className="scan-trade-card-title">
-              {isEn ? "Buy Yes" : "买入 Yes"}{" "}
-              {normalizeTemperatureLabel(displayRow.target_label, tempSymbol) || ""}
-            </div>
-            <p>
-              {formatPrice(getDetailSideAsk(yesRow, marketScan, "yes"))} →{" "}
-              {formatProbability(yesRow?.model_probability)}
-            </p>
-            <p className="positive">{formatPercent(yesRow?.edge_percent, true)} {isEn ? "edge" : "边际优势"}</p>
-            <p>
-              {isEn ? "Bid / Ask" : "买卖价"} {formatPrice(getDetailSideBid(yesRow, marketScan, "yes"))} /{" "}
-              {formatPrice(getDetailSideAsk(yesRow, marketScan, "yes"))}
-            </p>
+        <div className="scan-detail-section-title">
+          {isEn ? "Main Signal" : "主信号概况"}
+        </div>
+        <div className="scan-kv-list compact">
+          <div className="scan-kv">
+            <span>{isEn ? "Best Side" : "主方向"}</span>
+            <strong>{displayRow.side === "no" ? "NO" : "YES"}</strong>
           </div>
-          <div className="scan-trade-card sell">
-            <div className="scan-trade-card-title">
-              {isEn ? "Buy No" : "买入 No"}{" "}
-              {normalizeTemperatureLabel(displayRow.target_label, tempSymbol) || ""}
-            </div>
-            <p>
-              {formatPrice(getDetailSideAsk(noRow, marketScan, "no"))} →{" "}
-              {formatProbability(noRow?.model_probability)}
-            </p>
-            <p className={Number(noRow?.edge_percent || 0) >= 0 ? "positive" : "negative"}>
-              {formatPercent(noRow?.edge_percent, true)} {isEn ? "edge" : "边际优势"}
-            </p>
-            <p>
-              {isEn ? "Bid / Ask" : "买卖价"} {formatPrice(getDetailSideBid(noRow, marketScan, "no"))} /{" "}
-              {formatPrice(getDetailSideAsk(noRow, marketScan, "no"))}
-            </p>
+          <div className="scan-kv">
+            <span>{isEn ? "Best Buy" : "最优买价"}</span>
+            <strong>
+              {displayRow.side === "no"
+                ? formatPrice(getDetailSideAsk(noRow, marketScan, "no"))
+                : formatPrice(getDetailSideAsk(yesRow, marketScan, "yes"))}
+            </strong>
+          </div>
+          <div className="scan-kv">
+            <span>{isEn ? "EMOS" : "EMOS 概率"}</span>
+            <strong>
+              {displayRow.side === "no"
+                ? formatProbability(noRow?.model_probability)
+                : formatProbability(yesRow?.model_probability)}
+            </strong>
+          </div>
+          <div className="scan-kv">
+            <span>{isEn ? "Edge" : "边际优势"}</span>
+            <strong className={Number(displayRow.edge_percent || 0) >= 0 ? "positive" : "negative"}>
+              {formatPercent(displayRow.edge_percent, true)}
+            </strong>
           </div>
         </div>
       </section>
@@ -630,6 +595,11 @@ function CalendarView({
                 className={`scan-calendar-card ${selectedRowId === row.id ? "selected" : ""}`}
                 onClick={() => onSelectRow(row)}
               >
+                {(() => {
+                  const tempSymbol = row.temp_symbol || "°C";
+                  const phaseMeta = getWindowPhaseMeta(row, locale);
+                  return (
+                    <>
                 <div className="scan-calendar-city">
                   {getLocalizedCityName(
                     row.city,
@@ -637,13 +607,19 @@ function CalendarView({
                     locale,
                   )}
                 </div>
-                <div className={`scan-calendar-action ${row.side === "no" ? "sell" : "buy"}`}>
-                  {row.action || row.target_label || "--"}
+                <div className="scan-calendar-action">
+                  {locale === "en-US" ? "DEB high" : "DEB 预测高点"} ·{" "}
+                  {row.deb_prediction != null
+                    ? formatTemperatureValue(row.deb_prediction, tempSymbol)
+                    : "--"}
                 </div>
                 <div className="scan-calendar-meta">
                   <span>{row.local_time || "--"}</span>
-                  <span>{formatPercent(row.edge_percent, true)}</span>
+                  <span>{phaseMeta.label}</span>
                 </div>
+                    </>
+                  );
+                })()}
               </button>
             ))}
           </div>
@@ -670,97 +646,6 @@ function OverviewMapView({ locale }: { locale: string }) {
   );
 }
 
-function PortfolioView({
-  rows,
-  locale,
-}: {
-  rows: ScanOpportunityRow[];
-  locale: string;
-}) {
-  const yesCount = rows.filter((row) => row.side === "yes").length;
-  const noCount = rows.filter((row) => row.side === "no").length;
-  const avgScore =
-    rows.length > 0
-      ? rows.reduce((sum, row) => sum + Number(row.final_score || 0), 0) / rows.length
-      : null;
-
-  return (
-    <div className="scan-summary-grid">
-      <div className="scan-summary-card">
-        <div className="scan-summary-label">{locale === "en-US" ? "YES Ideas" : "YES 机会"}</div>
-        <div className="scan-summary-value">{yesCount}</div>
-      </div>
-      <div className="scan-summary-card">
-        <div className="scan-summary-label">{locale === "en-US" ? "NO Ideas" : "NO 机会"}</div>
-        <div className="scan-summary-value">{noCount}</div>
-      </div>
-      <div className="scan-summary-card wide">
-        <div className="scan-summary-label">{locale === "en-US" ? "Avg Score" : "平均评分"}</div>
-        <div className="scan-summary-value">
-          {avgScore != null ? `${avgScore.toFixed(0)}/100` : "--"}
-        </div>
-      </div>
-    </div>
-  );
-}
-
-function MonitorView({
-  rows,
-  locale,
-}: {
-  rows: ScanOpportunityRow[];
-  locale: string;
-}) {
-  const groups = useMemo(() => {
-    const result = new Map<string, number>();
-    rows.forEach((row) => {
-      const label = getWindowPhaseMeta(row, locale).label;
-      result.set(label, (result.get(label) || 0) + 1);
-    });
-    return Array.from(result.entries());
-  }, [rows, locale]);
-
-  return (
-    <div className="scan-summary-grid monitor">
-      {groups.map(([label, count]) => (
-        <div key={label} className="scan-summary-card">
-          <div className="scan-summary-label">{label}</div>
-          <div className="scan-summary-value">{count}</div>
-        </div>
-      ))}
-    </div>
-  );
-}
-
-function SettingsView({ locale }: { locale: string }) {
-  return (
-    <div className="scan-settings-view">
-      <div className="scan-settings-card">
-        <div className="scan-summary-label">{locale === "en-US" ? "Market Discovery" : "市场发现"}</div>
-        <div className="scan-settings-copy">
-          {locale === "en-US" ? "Gamma REST refreshes every 60s." : "Gamma REST 每 60 秒刷新一次。"}
-        </div>
-      </div>
-      <div className="scan-settings-card">
-        <div className="scan-summary-label">{locale === "en-US" ? "Price Layer" : "价格层"}</div>
-        <div className="scan-settings-copy">
-          {locale === "en-US"
-            ? "CLOB REST prices and books refresh every 30s."
-            : "CLOB REST 价格和盘口每 30 秒刷新一次。"}
-        </div>
-      </div>
-      <div className="scan-settings-card">
-        <div className="scan-summary-label">{locale === "en-US" ? "Server Profile" : "服务器配置"}</div>
-        <div className="scan-settings-copy">
-          {locale === "en-US"
-            ? "2GB profile: one polling loop, cached REST, no websocket fan-out."
-            : "2G 配置：单轮询、REST 缓存优先、不做 websocket 扇出。"}
-        </div>
-      </div>
-    </div>
-  );
-}
-
 function ScanTerminalScreen() {
   const store = useDashboardStore();
   const { locale, toggleLocale } = useI18n();
@@ -776,7 +661,6 @@ function ScanTerminalScreen() {
   const [selectedRowId, setSelectedRowId] = useState<string | null>(null);
   const [detailByRowId, setDetailByRowId] = useState<Record<string, MarketScan | null>>({});
   const [detailLoadingId, setDetailLoadingId] = useState<string | null>(null);
-  const [activeSection, setActiveSection] = useState<TopSection>("terminal");
   const [activeView, setActiveView] = useState<ContentView>("list");
   const [mapSelectedCityName, setMapSelectedCityName] = useState<string | null>(null);
   const [userLocalTime, setUserLocalTime] = useState("--");
@@ -806,12 +690,12 @@ function ScanTerminalScreen() {
 
   const fetchTerminal = async (filters: FilterState, force = false) => {
     setLoading(true);
-    setError(null);
     try {
       const response = await dashboardClient.getScanTerminal(filters, { force });
       startTransition(() => {
         setTerminalData(response);
         setActiveFilters(filters);
+        setError(response.status === "failed" ? response.stale_reason || null : null);
         setSelectedRowId((current) => {
           if (current && response.rows.some((row) => row.id === current)) {
             return current;
@@ -827,7 +711,7 @@ function ScanTerminalScreen() {
   };
 
   const fetchDetail = async (row: ScanOpportunityRow) => {
-    if (!row.market_slug || !row.selected_date) return;
+    if (!row.market_slug || !row.selected_date || row.closed) return;
     if (detailByRowId[row.id] !== undefined) return;
     setDetailLoadingId(row.id);
     try {
@@ -880,15 +764,13 @@ function ScanTerminalScreen() {
     window.localStorage.setItem("polyweather_scan_theme", themeMode);
   }, [themeMode]);
 
+  const resolvedView: ContentView = activeView;
   const mapFocusedCity = mapSelectedCityName || store.selectedCity;
-  const resolvedView: ContentView =
-    activeSection === "markets"
-      ? "map"
-      : activeSection === "analysis"
-        ? "calendar"
-        : activeView;
   const activeDetailRow = resolvedView === "map" && mapFocusedCity ? mapFocusedRow : selectedRow;
   const selectedDetail = activeDetailRow ? detailByRowId[activeDetailRow.id] : null;
+  const scanStatus = terminalData?.status || (loading ? "loading" : error ? "failed" : "ready");
+  const staleReason =
+    terminalData?.stale_reason || error || null;
 
   useEffect(() => {
     if (!activeDetailRow) return;
@@ -914,15 +796,6 @@ function ScanTerminalScreen() {
   }, []);
 
   const renderMainView = () => {
-    if (activeSection === "portfolio") {
-      return <PortfolioView rows={timeSortedRows} locale={locale} />;
-    }
-    if (activeSection === "monitor") {
-      return <MonitorView rows={timeSortedRows} locale={locale} />;
-    }
-    if (activeSection === "settings") {
-      return <SettingsView locale={locale} />;
-    }
     if (resolvedView === "map") {
       return (
         <div className="scan-map-view">
@@ -951,6 +824,10 @@ function ScanTerminalScreen() {
       <>
         <OpportunityTable
           rows={timeSortedRows}
+          status={scanStatus}
+          stale={Boolean(terminalData?.stale)}
+          staleReason={staleReason}
+          loading={loading}
           selectedRowId={selectedRowId}
           onSelectRow={handleSelectRow}
         />
@@ -973,19 +850,21 @@ function ScanTerminalScreen() {
 
         <main className="scan-data-grid">
           <div className="scan-topbar">
-            <div className="scan-topbar-tabs">
-              {NAV_ITEMS.map((item, index) => (
-                <button
-                  key={item.zh}
-                  type="button"
-                  className={`scan-topbar-tab ${
-                    TOP_SECTION_ORDER[index] === activeSection ? "active" : ""
-                  }`}
-                  onClick={() => setActiveSection(TOP_SECTION_ORDER[index])}
-                >
-                  {isEn ? item.en : item.zh}
-                </button>
-              ))}
+            <div className="scan-topbar-title">
+              <strong>{isEn ? "Market Scan Terminal" : "市场扫描台"}</strong>
+              <span>
+                {loading
+                  ? isEn
+                    ? "Refreshing current market snapshot"
+                    : "正在刷新当前市场快照"
+                  : terminalData?.stale
+                    ? isEn
+                      ? "Showing the last successful snapshot"
+                      : "当前显示上次成功快照"
+                    : isEn
+                      ? "Read-only market scan with peak-first main signal"
+                      : "只读市场扫描，主信号按 EMOS 主峰优先"}
+              </span>
             </div>
             <div className="scan-topbar-actions">
               <button
@@ -1012,11 +891,7 @@ function ScanTerminalScreen() {
               </button>
               <button type="button" className="scan-ghost-button" onClick={() => void fetchTerminal(activeFilters, true)}>
                 <RefreshCw size={14} className={loading ? "spin" : undefined} />
-                {isEn ? "Refresh" : "筛选"}
-              </button>
-              <button type="button" className="scan-cta-ghost">
-                <Bell size={14} />
-                {isEn ? "Custom Alerts" : "自定义提醒"}
+                {isEn ? "Refresh" : "刷新"}
               </button>
               <Link
                 href={accountHref}
@@ -1029,28 +904,11 @@ function ScanTerminalScreen() {
             </div>
           </div>
 
-          <section className="scan-hero">
-            <h1>{isEn ? "Tradable Opportunities" : "可交易机会"}</h1>
-            <p>
-              {isEn
-                ? "Use EMOS distribution, live order book, and timing windows to isolate the one actionable signal."
-                : "基于当前时间、实况数据和模型预测，筛选出最具交易价值的市场。"}
-            </p>
-          </section>
-
           <ScanKPIBar
-            data={
-              terminalData?.summary || {
-                recommended_count: 0,
-                visible_count: 0,
-                candidate_total: 0,
-                avg_edge_percent: null,
-                avg_primary_confidence: null,
-                tradable_market_count: 0,
-                total_volume: 0,
-                resolved_market_type: "maxtemp",
-              }
-            }
+            response={terminalData}
+            rows={timeSortedRows}
+            totalCities={store.cities.length}
+            loading={loading}
           />
 
           <section className="scan-list-section">
@@ -1058,9 +916,8 @@ function ScanTerminalScreen() {
               <div className="scan-list-tabs">
                 <button
                   type="button"
-                  className={activeSection === "terminal" && resolvedView === "list" ? "active" : ""}
+                  className={resolvedView === "list" ? "active" : ""}
                   onClick={() => {
-                    setActiveSection("terminal");
                     setActiveView("list");
                   }}
                 >
@@ -1070,7 +927,6 @@ function ScanTerminalScreen() {
                   type="button"
                   className={resolvedView === "map" ? "active" : ""}
                   onClick={() => {
-                    setActiveSection("terminal");
                     setActiveView("map");
                   }}
                 >
@@ -1080,39 +936,32 @@ function ScanTerminalScreen() {
                   type="button"
                   className={resolvedView === "calendar" ? "active" : ""}
                   onClick={() => {
-                    setActiveSection("terminal");
                     setActiveView("calendar");
                   }}
                 >
                   {isEn ? "Calendar View" : "日历视图"}
                 </button>
               </div>
-              <div className="scan-list-controls">
-                <div className="scan-sort-pill">
-                  {isEn
-                    ? resolvedView === "calendar"
-                      ? "Sort: Date"
-                    : resolvedView === "map"
-                        ? "Sort: City Map"
-                        : "Sort: Your Time"
-                    : resolvedView === "calendar"
-                      ? "排序：日期"
-                      : resolvedView === "map"
-                        ? "排序：地图"
-                        : "排序：用户时区时间"}
-                </div>
-                <button type="button" className="scan-icon-pill" aria-label="menu">
-                  <Menu size={16} />
-                </button>
+              <div className="scan-list-status">
+                {terminalData?.stale ? (
+                  <span className="scan-status-chip stale">
+                    {isEn ? "Delayed snapshot" : "延迟快照"}
+                  </span>
+                ) : null}
+                {loading ? (
+                  <span className="scan-status-chip live">
+                    {isEn ? "Refreshing" : "刷新中"}
+                  </span>
+                ) : null}
               </div>
             </div>
 
-            {error ? (
+            {scanStatus === "failed" && !terminalData ? (
               <div className="scan-empty-state">
                 <div className="scan-empty-title">
                   {isEn ? "Scan failed" : "扫描失败"}
                 </div>
-                <div className="scan-empty-copy">{error}</div>
+                <div className="scan-empty-copy">{staleReason}</div>
               </div>
             ) : (
               renderMainView()

frontend/lib/dashboard-types.ts

@@ -497,6 +497,11 @@ export interface ScanOpportunityRow {
   distribution_bias_direction?: string | null;
   distribution_bias_score?: number | null;
   distribution_bias_available?: boolean;
+  peak_probability?: number | null;
+  peak_value?: number | null;
+  peak_distance?: number | null;
+  peak_alignment_score?: number | null;
+  is_peak_candidate?: boolean;
   window_phase?: string | null;
   window_score?: number | null;
   remaining_window_minutes?: number | null;
@@ -525,6 +530,12 @@ export interface PrimarySignal extends ScanOpportunityRow {}
 
 export interface ScanTerminalResponse {
   generated_at: string;
+  snapshot_id?: string | null;
+  status?: "ready" | "stale" | "failed" | string;
+  stale?: boolean;
+  stale_reason?: string | null;
+  last_success_at?: string | null;
+  last_failed_at?: string | null;
   filters: ScanTerminalFilters;
   summary: {
     recommended_count: number;

src/data_collection/polymarket_readonly.py

@@ -2810,12 +2810,60 @@ class PolymarketReadOnlyLayer:
             )
             distribution_preview[highlighted_index]["highlighted"] = True
 
+        peak_probability = None
+        peak_value = None
+        if distribution_preview:
+            highlighted_preview = next(
+                (item for item in distribution_preview if item.get("highlighted")),
+                None,
+            )
+            if isinstance(highlighted_preview, dict):
+                peak_probability = _safe_float(highlighted_preview.get("model_probability"))
+                peak_value = _safe_float(highlighted_preview.get("value"))
+
+        ordered_entry_indices = sorted(
+            range(len(market_entries)),
+            key=lambda index: (
+                _safe_float(market_entries[index].get("bucket_temp"))
+                if _safe_float(market_entries[index].get("bucket_temp")) is not None
+                else float("inf"),
+                str(market_entries[index].get("target_label") or ""),
+            ),
+        )
+        entry_order_map = {
+            ordered_entry_indices[position]: position
+            for position in range(len(ordered_entry_indices))
+        }
+        peak_entry_order = None
+        if peak_value is not None and ordered_entry_indices:
+            peak_entry_order = min(
+                range(len(ordered_entry_indices)),
+                key=lambda position: abs(
+                    (
+                        _safe_float(
+                            market_entries[ordered_entry_indices[position]].get("bucket_temp")
+                        )
+                        if _safe_float(
+                            market_entries[ordered_entry_indices[position]].get("bucket_temp")
+                        )
+                        is not None
+                        else peak_value
+                    )
+                    - peak_value
+                ),
+            )
+
         current_reference_raw = _safe_float(
             (scan_context or {}).get("current_max_so_far")
             or (scan_context or {}).get("current_temp")
         )
 
-        def _row_from_entry(entry: Dict[str, Any], side: str) -> Optional[Dict[str, Any]]:
+        def _row_from_entry(
+            entry: Dict[str, Any],
+            side: str,
+            *,
+            entry_index: int,
+        ) -> Optional[Dict[str, Any]]:
             model_event_probability = _clamp_probability(_safe_float(entry.get("model_event_probability")))
             market_event_probability = _clamp_probability(_safe_float(entry.get("market_event_probability")))
             ask = _clamp_probability(_safe_float(entry.get("yes_ask") if side == "yes" else entry.get("no_ask")))
@@ -2850,6 +2898,21 @@ class PolymarketReadOnlyLayer:
                 if target_threshold is not None and current_reference is not None
                 else None
             )
+            entry_order = entry_order_map.get(entry_index)
+            peak_distance = None
+            is_peak_candidate = False
+            if entry_order is not None and peak_entry_order is not None:
+                peak_distance = abs(entry_order - peak_entry_order)
+                is_peak_candidate = peak_distance <= 1
+            peak_alignment_score = 0.0
+            if peak_distance is None:
+                peak_alignment_score = 0.35
+            elif peak_distance == 0:
+                peak_alignment_score = 1.0
+            elif peak_distance == 1:
+                peak_alignment_score = 0.8
+            else:
+                peak_alignment_score = max(0.0, 0.55 - 0.15 * float(peak_distance - 2))
             temperature_direction = self._resolve_temperature_direction(
                 side=side,
                 market_direction=str(entry.get("market_direction") or "exact"),
@@ -2899,6 +2962,7 @@ class PolymarketReadOnlyLayer:
                 + 0.20 * float(window_meta.get("score") or 0.0)
                 + 0.10 * liquidity_score
                 + 0.10 * price_usefulness_score
+                + 0.08 * peak_alignment_score
             ) - spread_penalty
             market_slug = str(market.get("slug") or "").strip()
             target_label = str(entry.get("target_label") or "").strip()
@@ -2974,6 +3038,11 @@ class PolymarketReadOnlyLayer:
                 "distribution_bias_score": distribution_bias_score,
                 "distribution_bias_available": distribution_bias["available"],
                 "distribution_preview": distribution_preview[:6],
+                "peak_probability": peak_probability,
+                "peak_value": peak_value,
+                "peak_distance": peak_distance,
+                "peak_alignment_score": peak_alignment_score,
+                "is_peak_candidate": is_peak_candidate,
                 "current_reference": current_reference,
                 "gap_to_target": gap_to_target,
                 "touch_distance": abs(gap_to_target) if gap_to_target is not None else None,
@@ -2991,9 +3060,9 @@ class PolymarketReadOnlyLayer:
             }
 
         preliminary_rows: List[Dict[str, Any]] = []
-        for entry in market_entries:
-            row_yes = _row_from_entry(entry, "yes")
-            row_no = _row_from_entry(entry, "no")
+        for entry_index, entry in enumerate(market_entries):
+            row_yes = _row_from_entry(entry, "yes", entry_index=entry_index)
+            row_no = _row_from_entry(entry, "no", entry_index=entry_index)
             if row_yes:
                 preliminary_rows.append(row_yes)
             if row_no:
@@ -3041,9 +3110,9 @@ class PolymarketReadOnlyLayer:
                 entry["spread"] = max(0.0, float(entry["yes_ask"]) - float(entry["yes_bid"]))
 
         final_rows: List[Dict[str, Any]] = []
-        for entry in market_entries:
+        for entry_index, entry in enumerate(market_entries):
             for side in ("yes", "no"):
-                row = _row_from_entry(entry, side)
+                row = _row_from_entry(entry, side, entry_index=entry_index)
                 if row:
                     final_rows.append(row)
 
@@ -3074,7 +3143,10 @@ class PolymarketReadOnlyLayer:
         def _passes_mode_filters(row: Dict[str, Any]) -> bool:
             scan_mode = filters["scan_mode"]
             if scan_mode == "tradable":
-                return float(row.get("window_score") or 0.0) >= 0.65
+                return (
+                    float(row.get("window_score") or 0.0) >= 0.65
+                    and bool(row.get("is_peak_candidate"))
+                )
             if scan_mode == "early":
                 return str(row.get("window_phase") or "") in {"tomorrow", "week_ahead", "early_today"}
             if scan_mode == "touch":
@@ -3095,6 +3167,7 @@ class PolymarketReadOnlyLayer:
         ]
         filtered_rows.sort(
             key=lambda row: (
+                1.0 if bool(row.get("is_peak_candidate")) else 0.0,
                 float(row.get("final_score") or 0.0),
                 float(row.get("edge_percent") or 0.0),
             ),

tests/test_polymarket_readonly.py

@@ -675,6 +675,39 @@ def test_distribution_scan_hard_filters_block_unusable_extreme_quotes():
     assert scan["rows"] == []
 
 
+def test_distribution_scan_tradable_prefers_peak_bucket_and_adjacent_only():
+    layer, markets = _build_scan_test_layer()
+
+    scan = layer._build_distribution_scan_pack(
+        city_key="wellington",
+        target_date="2026-04-24",
+        primary_market=markets[0],
+        probability_distribution=[
+            {"value": 14, "probability": 20},
+            {"value": 15, "probability": 48},
+            {"value": 16, "probability": 24},
+            {"value": 17, "probability": 8},
+        ],
+        temp_symbol="°C",
+        scan_context={
+            "local_date": "2026-04-24",
+            "local_time": "13:10",
+            "peak": {"first_h": 14, "last_h": 16},
+            "current_max_so_far": 13.6,
+            "current_temp": 13.2,
+            "trend": {"recent": []},
+            "network_lead_signal": {},
+        },
+        scan_filters={"limit": 10, "scan_mode": "tradable", "min_edge_pct": 2},
+    )
+
+    assert scan["signal_status"] == "ready"
+    assert scan["primary_signal"]["is_peak_candidate"] is True
+    assert scan["primary_signal"]["peak_distance"] in {0, 1}
+    assert all(bool(row.get("is_peak_candidate")) for row in scan["rows"])
+    assert all((row.get("peak_distance") or 0) <= 1 for row in scan["rows"])
+
+
 def test_batch_token_market_data_falls_back_to_single_fetch_when_batch_fails():
     layer = PolymarketReadOnlyLayer()
     layer._clob_post = lambda *_args, **_kwargs: None

tests/test_web_observability.py

@@ -3,6 +3,7 @@ from fastapi.testclient import TestClient
 
 from web.app import app
 import web.routes as routes
+import web.scan_terminal_service as scan_terminal_service
 from web.scan_terminal_service import _scan_terminal_cache_key
 from src.database.db_manager import DBManager
 from src.database.runtime_state import TruthRecordRepository, TrainingFeatureRecordRepository
@@ -258,7 +259,66 @@ def test_ops_truth_history_returns_filtered_rows(monkeypatch):
     assert "items" in payload
     assert payload["filters"]["city"] == "taipei"
     assert payload["items"][0]["city"] == "taipei"
-    assert payload["items"][0]["settlement_station_code"] == "RCSS"
+
+
+def test_scan_terminal_service_returns_stale_payload_after_failed_refresh(monkeypatch):
+    filters = {"scan_mode": "tradable", "limit": 5}
+    normalized_filters = scan_terminal_service._normalize_scan_terminal_filters(filters)
+    scan_terminal_service._SCAN_TERMINAL_CACHE.clear()
+
+    monkeypatch.setattr(
+        scan_terminal_service,
+        "_scan_city_terminal_rows",
+        lambda *_args, **_kwargs: {
+            "city": "taipei",
+            "rows": [
+                {
+                    "id": "row-1",
+                    "market_key": "market-1",
+                    "edge_percent": 12.4,
+                    "final_score": 83.0,
+                    "volume": 2000,
+                }
+            ],
+            "candidate_total": 1,
+            "primary_scores": [83.0],
+        },
+    )
+
+    ready = scan_terminal_service.build_scan_terminal_payload(filters, force_refresh=True)
+    assert ready["status"] == "ready"
+    assert ready["rows"][0]["id"] == "row-1"
+
+    def _explode(*_args, **_kwargs):
+        raise RuntimeError("upstream 504")
+
+    monkeypatch.setattr(scan_terminal_service, "_scan_city_terminal_rows", _explode)
+
+    stale = scan_terminal_service.build_scan_terminal_payload(filters, force_refresh=True)
+
+    assert stale["status"] == "stale"
+    assert stale["stale"] is True
+    assert stale["rows"][0]["id"] == "row-1"
+    assert stale["filters"] == normalized_filters
+    assert stale["stale_reason"] == "upstream 504"
+
+
+def test_scan_terminal_service_returns_failed_without_success_snapshot(monkeypatch):
+    filters = {"scan_mode": "tradable", "limit": 5}
+    scan_terminal_service._SCAN_TERMINAL_CACHE.clear()
+
+    def _explode(*_args, **_kwargs):
+        raise RuntimeError("network down")
+
+    monkeypatch.setattr(scan_terminal_service, "_scan_city_terminal_rows", _explode)
+
+    failed = scan_terminal_service.build_scan_terminal_payload(filters, force_refresh=True)
+
+    assert failed["status"] == "failed"
+    assert failed["stale"] is False
+    assert failed["rows"] == []
+    assert failed["summary"]["candidate_total"] == 0
+    assert failed["stale_reason"] == "network down"
 
 
 def test_scan_terminal_endpoint_forwards_filters(monkeypatch):

web/scan_terminal_service.py

@@ -4,6 +4,7 @@ import json
 import os
 import threading
 import time
+import hashlib
 from concurrent.futures import ThreadPoolExecutor, as_completed
 from datetime import datetime, timedelta
 from typing import Any, Dict, List, Optional
@@ -99,18 +100,125 @@ def _get_cached_scan_terminal_payload(
         return dict(payload)
 
 
+def _get_scan_terminal_cache_entry(filters: Dict[str, Any]) -> Optional[Dict[str, Any]]:
+    cache_key = _scan_terminal_cache_key(filters)
+    with _SCAN_TERMINAL_CACHE_LOCK:
+        cached = _SCAN_TERMINAL_CACHE.get(cache_key)
+        if not isinstance(cached, dict):
+            return None
+        return dict(cached)
+
+
+def _build_scan_terminal_snapshot_id(
+    filters: Dict[str, Any],
+    rows: List[Dict[str, Any]],
+    summary: Dict[str, Any],
+    top_signal: Optional[Dict[str, Any]],
+) -> str:
+    seed_payload = {
+        "filters": filters,
+        "summary": {
+            "candidate_total": summary.get("candidate_total"),
+            "tradable_market_count": summary.get("tradable_market_count"),
+            "avg_edge_percent": summary.get("avg_edge_percent"),
+        },
+        "top_signal": {
+            "id": (top_signal or {}).get("id"),
+            "edge_percent": (top_signal or {}).get("edge_percent"),
+            "final_score": (top_signal or {}).get("final_score"),
+        },
+        "rows": [
+            {
+                "id": row.get("id"),
+                "edge_percent": row.get("edge_percent"),
+                "final_score": row.get("final_score"),
+            }
+            for row in rows[:10]
+        ],
+    }
+    digest = hashlib.md5(
+        json.dumps(seed_payload, ensure_ascii=True, sort_keys=True).encode("utf-8")
+    ).hexdigest()
+    return f"scan-{digest[:10]}"
+
+
 def _set_cached_scan_terminal_payload(
     filters: Dict[str, Any],
     payload: Dict[str, Any],
 ) -> None:
     cache_key = _scan_terminal_cache_key(filters)
+    existing = _get_scan_terminal_cache_entry(filters) or {}
     with _SCAN_TERMINAL_CACHE_LOCK:
         _SCAN_TERMINAL_CACHE[cache_key] = {
             "t": time.time(),
             "payload": dict(payload),
+            "success_t": time.time(),
+            "success_payload": dict(payload),
+            "last_error": existing.get("last_error"),
+            "last_failed_at": existing.get("last_failed_at"),
         }
 
 
+def _set_scan_terminal_failure_state(
+    filters: Dict[str, Any],
+    *,
+    error_message: str,
+) -> None:
+    cache_key = _scan_terminal_cache_key(filters)
+    with _SCAN_TERMINAL_CACHE_LOCK:
+        existing = _SCAN_TERMINAL_CACHE.get(cache_key) or {}
+        existing["last_error"] = error_message
+        existing["last_failed_at"] = datetime.utcnow().isoformat() + "Z"
+        _SCAN_TERMINAL_CACHE[cache_key] = existing
+
+
+def _build_stale_scan_terminal_payload(
+    *,
+    filters: Dict[str, Any],
+    success_payload: Dict[str, Any],
+    error_message: str,
+    failed_at: Optional[str],
+) -> Dict[str, Any]:
+    payload = dict(success_payload)
+    payload["status"] = "stale"
+    payload["stale"] = True
+    payload["stale_reason"] = error_message
+    payload["last_success_at"] = success_payload.get("generated_at")
+    payload["last_failed_at"] = failed_at
+    payload["filters"] = filters
+    return payload
+
+
+def _build_failed_scan_terminal_payload(
+    *,
+    filters: Dict[str, Any],
+    error_message: str,
+    failed_at: Optional[str] = None,
+) -> Dict[str, Any]:
+    return {
+        "generated_at": datetime.utcnow().isoformat() + "Z",
+        "snapshot_id": None,
+        "status": "failed",
+        "stale": False,
+        "stale_reason": error_message,
+        "last_success_at": None,
+        "last_failed_at": failed_at or (datetime.utcnow().isoformat() + "Z"),
+        "filters": filters,
+        "summary": {
+            "recommended_count": 0,
+            "visible_count": 0,
+            "candidate_total": 0,
+            "avg_edge_percent": None,
+            "avg_primary_confidence": None,
+            "tradable_market_count": 0,
+            "total_volume": 0.0,
+            "resolved_market_type": "maxtemp",
+        },
+        "top_signal": None,
+        "rows": [],
+    }
+
+
 def _resolve_time_range_dates(data: Dict[str, Any], time_range: str) -> List[str]:
     local_date = str(data.get("local_date") or "").strip()
     multi_model_daily = data.get("multi_model_daily") or {}
@@ -265,83 +373,105 @@ def build_scan_terminal_payload(
         cached = _get_cached_scan_terminal_payload(filters)
         if cached is not None:
             return cached
+    cached_entry = _get_scan_terminal_cache_entry(filters) or {}
 
-    city_names = list(CITIES.keys())
-    max_workers = max(1, min(6, len(city_names)))
-    city_results: List[Dict[str, Any]] = []
+    try:
+        city_names = list(CITIES.keys())
+        max_workers = max(1, min(4, len(city_names)))
+        city_results: List[Dict[str, Any]] = []
+        failed_cities: List[str] = []
+        failed_reasons: List[str] = []
 
-    with ThreadPoolExecutor(max_workers=max_workers) as executor:
-        future_map = {
-            executor.submit(
-                _scan_city_terminal_rows,
-                city_name,
-                filters,
-                force_refresh=force_refresh,
-            ): city_name
-            for city_name in city_names
-        }
-        for future in as_completed(future_map):
-            city_name = future_map[future]
-            try:
-                city_results.append(future.result())
-            except Exception as exc:
-                logger.warning("scan terminal city failed city={}: {}", city_name, exc)
-
-    primary_rows: List[Dict[str, Any]] = []
-    primary_scores: List[float] = []
-    candidate_total = 0
-
-    for result in city_results:
-        candidate_total += int(result.get("candidate_total") or 0)
-        primary_rows.extend(result.get("rows") or [])
-        primary_scores.extend(result.get("primary_scores") or [])
-
-    primary_rows.sort(
-        key=lambda row: (
-            float(row.get("final_score") or 0.0),
-            float(row.get("edge_percent") or 0.0),
-        ),
-        reverse=True,
-    )
-
-    ranked_rows: List[Dict[str, Any]] = []
-    for index, row in enumerate(primary_rows[: filters["limit"]], start=1):
-        ranked_rows.append(
-            {
-                **row,
-                "rank": index,
+        with ThreadPoolExecutor(max_workers=max_workers) as executor:
+            future_map = {
+                executor.submit(
+                    _scan_city_terminal_rows,
+                    city_name,
+                    filters,
+                    force_refresh=force_refresh,
+                ): city_name
+                for city_name in city_names
             }
+            for future in as_completed(future_map):
+                city_name = future_map[future]
+                try:
+                    city_results.append(future.result())
+                except Exception as exc:
+                    failed_cities.append(city_name)
+                    failed_reasons.append(str(exc))
+                    logger.warning("scan terminal city failed city={}: {}", city_name, exc)
+
+        if city_names and len(failed_cities) >= len(city_names):
+            error_message = failed_reasons[0] if failed_reasons else "all city market scans failed"
+            _set_scan_terminal_failure_state(filters, error_message=error_message)
+            failed_entry = _get_scan_terminal_cache_entry(filters) or {}
+            success_payload = failed_entry.get("success_payload")
+            failed_at = failed_entry.get("last_failed_at")
+            if isinstance(success_payload, dict) and success_payload:
+                return _build_stale_scan_terminal_payload(
+                    filters=filters,
+                    success_payload=success_payload,
+                    error_message=error_message,
+                    failed_at=failed_at,
+                )
+            return _build_failed_scan_terminal_payload(
+                filters=filters,
+                error_message=error_message,
+                failed_at=failed_at,
+            )
+
+        primary_rows: List[Dict[str, Any]] = []
+        primary_scores: List[float] = []
+        candidate_total = 0
+
+        for result in city_results:
+            candidate_total += int(result.get("candidate_total") or 0)
+            primary_rows.extend(result.get("rows") or [])
+            primary_scores.extend(result.get("primary_scores") or [])
+
+        primary_rows.sort(
+            key=lambda row: (
+                float(row.get("final_score") or 0.0),
+                float(row.get("edge_percent") or 0.0),
+            ),
+            reverse=True,
         )
 
-    unique_market_volume: Dict[str, float] = {}
-    for row in primary_rows:
-        market_key = str(row.get("market_key") or row.get("id") or "").strip()
-        if not market_key:
-            continue
-        unique_market_volume[market_key] = max(
-            unique_market_volume.get(market_key, 0.0),
-            float(row.get("volume") or 0.0),
-        )
+        ranked_rows: List[Dict[str, Any]] = []
+        for index, row in enumerate(primary_rows[: filters["limit"]], start=1):
+            ranked_rows.append(
+                {
+                    **row,
+                    "rank": index,
+                }
+            )
 
-    avg_edge = None
-    if primary_rows:
-        edge_values = [
-            float(row.get("edge_percent") or 0.0)
-            for row in primary_rows
-            if _safe_float(row.get("edge_percent")) is not None
-        ]
-        if edge_values:
-            avg_edge = sum(edge_values) / len(edge_values)
+        unique_market_volume: Dict[str, float] = {}
+        for row in primary_rows:
+            market_key = str(row.get("market_key") or row.get("id") or "").strip()
+            if not market_key:
+                continue
+            unique_market_volume[market_key] = max(
+                unique_market_volume.get(market_key, 0.0),
+                float(row.get("volume") or 0.0),
+            )
 
-    avg_confidence = None
-    if primary_scores:
-        avg_confidence = sum(primary_scores) / len(primary_scores)
+        avg_edge = None
+        if primary_rows:
+            edge_values = [
+                float(row.get("edge_percent") or 0.0)
+                for row in primary_rows
+                if _safe_float(row.get("edge_percent")) is not None
+            ]
+            if edge_values:
+                avg_edge = sum(edge_values) / len(edge_values)
 
-    top_signal = ranked_rows[0] if ranked_rows else None
-    payload = {
-        "generated_at": datetime.utcnow().isoformat() + "Z",
-        "filters": filters,
-        "summary": {
+        avg_confidence = None
+        if primary_scores:
+            avg_confidence = sum(primary_scores) / len(primary_scores)
+
+        top_signal = ranked_rows[0] if ranked_rows else None
+        summary = {
             "recommended_count": len(primary_rows),
             "visible_count": len(ranked_rows),
             "candidate_total": candidate_total,
@@ -350,10 +480,43 @@ def build_scan_terminal_payload(
             "tradable_market_count": len(unique_market_volume),
             "total_volume": sum(unique_market_volume.values()),
             "resolved_market_type": "maxtemp",
-        },
-        "top_signal": top_signal,
-        "rows": ranked_rows,
-    }
+        }
+        payload = {
+            "generated_at": datetime.utcnow().isoformat() + "Z",
+            "filters": filters,
+            "summary": summary,
+            "top_signal": top_signal,
+            "rows": ranked_rows,
+            "status": "ready",
+            "stale": False,
+            "stale_reason": None,
+            "last_success_at": None,
+            "last_failed_at": None,
+        }
+        payload["snapshot_id"] = _build_scan_terminal_snapshot_id(
+            filters,
+            ranked_rows,
+            summary,
+            top_signal,
+        )
 
-    _set_cached_scan_terminal_payload(filters, payload)
-    return payload
+        _set_cached_scan_terminal_payload(filters, payload)
+        return payload
+    except Exception as exc:
+        error_message = str(exc)
+        logger.exception("scan terminal payload build failed: {}", error_message)
+        _set_scan_terminal_failure_state(filters, error_message=error_message)
+        success_payload = cached_entry.get("success_payload")
+        failed_at = _get_scan_terminal_cache_entry(filters).get("last_failed_at") if _get_scan_terminal_cache_entry(filters) else None
+        if isinstance(success_payload, dict) and success_payload:
+            return _build_stale_scan_terminal_payload(
+                filters=filters,
+                success_payload=success_payload,
+                error_message=error_message,
+                failed_at=failed_at,
+            )
+        return _build_failed_scan_terminal_payload(
+            filters=filters,
+            error_message=error_message,
+            failed_at=failed_at,
+        )