修复告警中心4个Bug：时间显示0001-01-01、统计卡片全0、新增告警类型无标签、机床下拉为空

1. AlertRepository SQL缺少列别名致Dapper无法映射created_at→CreatedAt
2. AlertStatisticsResponse返回嵌套unresolvedByType,前端期望扁平collectFail等
3. AlertPage缺少production_error/summary_error的中文标签映射
4. 机床下拉模板用m.id/m.name,API返回value/label格式不匹配

frontend/src/views/alert/AlertPage.vue

@@ -18,6 +18,8 @@
           <el-option label="产量异常" value="production_anomaly" />
           <el-option label="未知设备" value="unknown_device" />
           <el-option label="服务错误" value="service_error" />
+          <el-option label="产量跟踪异常" value="production_error" />
+          <el-option label="日终汇总异常" value="summary_error" />
         </el-select>
       </el-form-item>
       <el-form-item label="处理状态">
@@ -31,7 +33,7 @@
       </el-form-item>
       <el-form-item label="机床">
         <el-select v-model="query.machineId" filterable clearable placeholder="全部">
-          <el-option v-for="m in machineList" :key="m.id" :label="m.name" :value="m.id" />
+          <el-option v-for="m in machineList" :key="(m as any).value ?? m.id" :label="(m as any).label ?? m.name" :value="(m as any).value ?? m.id" />
         </el-select>
       </el-form-item>
       <el-form-item>
@@ -146,6 +148,8 @@ function alertTypeTag(type: string): string {
     production_anomaly: 'warning',
     unknown_device: 'info',
     service_error: 'danger',
+    production_error: 'danger',
+    summary_error: 'danger',
   }
   return map[type] || 'info'
 }
@@ -157,6 +161,8 @@ function alertTypeLabel(type: string): string {
     production_anomaly: '产量异常',
     unknown_device: '未知设备',
     service_error: '服务错误',
+    production_error: '产量跟踪异常',
+    summary_error: '日终汇总异常',
   }
   return map[type] || type
 }

src/CncModels/Dto/Alert/AlertStatisticsResponse.cs

@@ -7,10 +7,27 @@ namespace CncModels.Dto.Alert
     /// </summary>
     public class AlertStatisticsResponse
     {
-        /// <summary>未处理告警总数</summary>
+        /// <summary>未处理告警总数（前端用 unresolved）</summary>
         public int UnresolvedCount { get; set; }
 
         /// <summary>按告警类型统计的未处理数量</summary>
         public Dictionary<string, int> UnresolvedByType { get; set; } = new Dictionary<string, int>();
+
+        // 以下为前端 AlertStats 接口需要的扁平字段
+
+        /// <summary>未处理总数（前端字段名 unresolved）</summary>
+        public int Unresolved => UnresolvedCount;
+
+        /// <summary>采集失败未处理数</summary>
+        public int CollectFail => UnresolvedByType.TryGetValue("collect_fail", out var v) ? v : 0;
+
+        /// <summary>设备离线未处理数</summary>
+        public int DeviceOffline => UnresolvedByType.TryGetValue("device_offline", out var v) ? v : 0;
+
+        /// <summary>产量异常未处理数</summary>
+        public int ProductionAnomaly => UnresolvedByType.TryGetValue("production_anomaly", out var v) ? v : 0;
+
+        /// <summary>未知设备未处理数</summary>
+        public int UnknownDevice => UnresolvedByType.TryGetValue("unknown_device", out var v) ? v : 0;
     }
 }

src/CncRepository/Impl/AlertRepository.cs

@@ -30,7 +30,7 @@ namespace CncRepository.Impl
         {
             using (var conn = CreateConnection())
             {
-                string sql = @"SELECT a.id, a.created_at, a.alert_type, a.title, m.name AS MachineName, a.detail, a.is_resolved, a.resolved_at
+                string sql = @"SELECT a.id AS Id, a.created_at AS CreatedAt, a.alert_type AS AlertType, a.title AS Title, m.name AS MachineName, a.detail AS Detail, a.is_resolved AS IsResolved, a.resolved_at AS ResolvedAt
                                 FROM cnc_alert a LEFT JOIN cnc_machine m ON a.machine_id = m.id
                                 WHERE 1=1";
                 string countSql = @"SELECT COUNT(*) FROM cnc_alert a LEFT JOIN cnc_machine m ON a.machine_id = m.id WHERE 1=1";