MiMo AI 能力扩展：TAF解读、概率分布解读、异常检测、市场概览

AI 解读字段扩展:
    - 新增 taf_read_zh/en：解读机场预报中影响今日峰值窗口的变化
    - 新增 probability_read_zh/en：描述概率分布形态（最高桶、偏左/偏右）
    - stream max_tokens 900→1200 容纳新输出字段
    - 缓存 key 简化为 METAR原文+观测时间，大幅提升命中率
    - 兜底函数补全 TAF 和概率字段的确定性生成

    异常检测:
    - 纯数学计算，零 AI 延迟：实测温度 vs 全部模型预测上下限
    - 三级告警：breakout_above / breakout_below / deviation

    市场概览:
    - 新增 POST /api/scan/terminal/overview（MiMo 批量解读，缓存10分钟）
    - 前端 MarketOverviewBanner 可折叠横幅（顶栏与标签栏之间）
    - 移动端适配 640px/768px 断点，暗色/亮色双主题

    Scope-risk: MEDIUM — 170 测试通过，TypeScript 零错误，ruff 零告警
    Tested: python -m pytest -q (170 passed), npx tsc --noEmit (0 errors), ruff check .

frontend/components/dashboard/scan-terminal/MarketOverviewBanner.tsx

@@ -0,0 +1,132 @@
+"use client";
+
+import clsx from "clsx";
+import { ChevronDown, ChevronUp, Sparkles } from "lucide-react";
+import { useCallback, useEffect, useRef, useState } from "react";
+import styles from "./MarketOverviewBanner.module.css";
+import type { ScanOpportunityRow } from "@/lib/dashboard-types";
+
+interface OverviewPayload {
+  overview_zh: string;
+  overview_en: string;
+  highlights: Array<{ city: string; note_zh: string; note_en: string }>;
+  generated_at: string | null;
+}
+
+export function MarketOverviewBanner({
+  isEn,
+  isPro,
+  rows,
+}: {
+  isEn: boolean;
+  isPro: boolean;
+  rows: ScanOpportunityRow[];
+}) {
+  const [collapsed, setCollapsed] = useState(true);
+  const [data, setData] = useState<OverviewPayload | null>(null);
+  const [loading, setLoading] = useState(false);
+  const [error, setError] = useState(false);
+  const fetchedRef = useRef(false);
+
+  const fetchOverview = useCallback(async () => {
+    if (!isPro || !rows.length || fetchedRef.current) return;
+    fetchedRef.current = true;
+    setLoading(true);
+    setError(false);
+    try {
+      const resp = await fetch("/api/scan/terminal/overview", {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({
+          rows: rows.slice(0, 40).map((row) => ({
+            city: row.city ?? row.display_name ?? "",
+            display_name: row.display_name ?? row.city ?? "",
+            local_date: row.local_date ?? "",
+            deb_prediction: row.deb_prediction ?? null,
+            current_temp: row.current_temp ?? null,
+            current_max_so_far: row.current_max_so_far ?? null,
+            risk_level: row.risk_level ?? "",
+            temp_symbol: row.temp_symbol ?? "°C",
+          })),
+        }),
+      });
+      if (resp.ok) {
+        const json = await resp.json();
+        setData(json);
+      } else {
+        setError(true);
+      }
+    } catch {
+      setError(true);
+    } finally {
+      setLoading(false);
+    }
+  }, [isPro, rows]);
+
+  useEffect(() => {
+    if (isPro && rows.length > 0 && !fetchedRef.current) {
+      fetchOverview();
+    }
+  }, [isPro, rows.length, fetchOverview]);
+
+  if (!isPro || rows.length === 0) return null;
+  if (loading && !data) {
+    return (
+      <div className={clsx(styles.root, styles.loading)}>
+        <Sparkles size={14} className={styles.icon} />
+        <span>{isEn ? "AI is generating market overview…" : "AI 正在生成市场概览…"}</span>
+      </div>
+    );
+  }
+  if (error && !data) return null;
+
+  const overviewText = data ? (isEn ? data.overview_en : data.overview_zh) : "";
+  const highlights = data?.highlights ?? [];
+
+  return (
+    <div className={clsx(styles.root, collapsed && styles.collapsed)}>
+      <button
+        type="button"
+        className={styles.header}
+        onClick={() => setCollapsed((c) => !c)}
+        aria-label={isEn ? "Toggle market overview" : "切换市场概览"}
+      >
+        <span className={styles.badge}>
+          <Sparkles size={13} />
+          {isEn ? "AI Overview" : "AI 概览"}
+        </span>
+        <span className={styles.preview}>
+          {collapsed && overviewText ? overviewText.slice(0, isEn ? 120 : 60) + "…" : ""}
+        </span>
+        <span className={styles.toggle}>
+          {collapsed ? <ChevronDown size={16} /> : <ChevronUp size={16} />}
+        </span>
+      </button>
+
+      {!collapsed && (
+        <div className={styles.body}>
+          <p className={styles.summary}>{overviewText}</p>
+          {highlights.length > 0 && (
+            <ul className={styles.highlights}>
+              {highlights.map((h) => (
+                <li key={h.city} className={styles.highlightItem}>
+                  <strong>{h.city}</strong>
+                  <span>{isEn ? h.note_en : h.note_zh}</span>
+                </li>
+              ))}
+            </ul>
+          )}
+          {data?.generated_at && (
+            <time className={styles.time} dateTime={data.generated_at}>
+              {isEn ? "Generated " : "生成于 "}
+              {new Date(data.generated_at).toLocaleTimeString(isEn ? "en-US" : "zh-CN", {
+                hour: "2-digit",
+                minute: "2-digit",
+              })}
+            </time>
+          )}
+        </div>
+      )}
+    </div>
+  );
+}