fix(mileage): 当日未对接但有历史 totalKm 的车今日里程显示 0 不是「未对接」

承接上一笔修复：兜底拿到 totalKm 后，今日里程也应该理解为 0（这车
在系统里有数据，只是今天没增量），而不是再贴「未对接」标签。

涉及：
- MonitoringView 表格 + 卡片：dailyKm 显示与对应颜色 / amber 点
- xlsx-export「今日里程」列

判定改成 (isDataSynced || totalKm != null)；
isOnline / 在线-离线 标签不变（基于 dailyKm > 0，与本次语义无关）。

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/modules/mileage/MonitoringView.tsx

@@ -528,15 +528,15 @@ export default function MonitoringView() {
                     {fullscreenVehicles.map((v) => (
                       <tr key={v.plate} className="hover:bg-slate-800/20 transition-colors">
                         <td className="px-3 py-2 text-center">
-                          <div className={`w-2 h-2 rounded-full mx-auto ${v.isOnline ? 'bg-green-500 shadow-[0_0_6px_rgba(34,197,94,0.4)]' : v.isDataSynced ? 'bg-slate-600' : 'bg-amber-400 animate-pulse'}`}></div>
+                          <div className={`w-2 h-2 rounded-full mx-auto ${v.isOnline ? 'bg-green-500 shadow-[0_0_6px_rgba(34,197,94,0.4)]' : (v.isDataSynced || v.totalKm != null) ? 'bg-slate-600' : 'bg-amber-400 animate-pulse'}`}></div>
                         </td>
                         <td className="px-3 py-2 text-xs font-bold text-white"><Blur>{v.plate}</Blur></td>
                         <td className="px-3 py-2 text-[11px] text-slate-400"><Blur>{v.customer || '-'}</Blur></td>
                         <td className="px-3 py-2 text-[11px] text-slate-400">{v.rentStatus || '-'}</td>
                         <td className="px-3 py-2 text-[11px] text-slate-400">{v.department || '-'}</td>
                         <td className="px-3 py-2 text-right">
-                          <span className={`text-xs font-mono font-bold ${v.isDataSynced ? 'text-blue-400' : 'text-amber-400'}`}>
+                          <span className={`text-xs font-mono font-bold ${(v.isDataSynced || v.totalKm != null) ? 'text-blue-400' : 'text-amber-400'}`}>
-                            {v.isDataSynced ? <>{Math.max(0, v.dailyKm || 0).toLocaleString()} <span className="text-[8px] text-slate-500">km</span></> : <span className="text-[8px] text-amber-500/50">未对接</span>}
+                            {(v.isDataSynced || v.totalKm != null) ? <>{Math.max(0, v.dailyKm || 0).toLocaleString()} <span className="text-[8px] text-slate-500">km</span></> : <span className="text-[8px] text-amber-500/50">未对接</span>}
                           </span>
                         </td>
                         <td className="px-3 py-2 text-right">
@@ -926,12 +926,12 @@ export default function MonitoringView() {
               </div>
               <div className="text-right flex-shrink-0 ml-2 flex flex-col items-end">
                 <div className="flex items-center gap-1 mb-0.5">
-                  {!v.isDataSynced && (
+                  {!v.isDataSynced && v.totalKm == null && (
                     <div className="w-2 h-2 rounded-full bg-amber-400 animate-pulse" title="未对接车机数据"></div>
                   )}
                   <span className="text-[7px] font-black text-blue-600/40 bg-blue-50 w-3 h-3 rounded flex items-center justify-center leading-none">今</span>
-                  <div className={`text-sm font-black leading-none ${v.isDataSynced ? 'text-blue-600' : 'text-amber-600'}`}>
+                  <div className={`text-sm font-black leading-none ${(v.isDataSynced || v.totalKm != null) ? 'text-blue-600' : 'text-amber-600'}`}>
-                    {v.isDataSynced ? <>{Math.max(0, v.dailyKm || 0).toLocaleString()} <span className="text-[8px] text-slate-400">km</span></> : <span className="text-[7px] text-amber-500/70">未对接</span>}
+                    {(v.isDataSynced || v.totalKm != null) ? <>{Math.max(0, v.dailyKm || 0).toLocaleString()} <span className="text-[8px] text-slate-400">km</span></> : <span className="text-[7px] text-amber-500/70">未对接</span>}
                   </div>
                 </div>
                 <div className="flex items-center gap-1">

src/modules/mileage/xlsx-export.ts

@@ -18,10 +18,10 @@ function statusLabel(v: MonitoringVehicle): string {
 
 function mileageCell(v: MonitoringVehicle, kind: 'today' | 'total'): string | number {
   if (kind === 'today') {
-    if (!v.isDataSynced) return '未对接';
+    // 当日未对接但有历史累计，视作今日 0；只有完全无数据才标「未对接」
+    if (!v.isDataSynced && v.totalKm == null) return '未对接';
     return Math.max(0, Math.round(v.dailyKm || 0));
   }
-  // 累计里程：当日未对接也允许使用历史兜底值
   return v.totalKm != null ? Math.round(v.totalKm) : '未对接';
 }