修复产量报表日期显示错误：value-format从yyyy-MM-dd改为YYYY-MM-DD（Element Plus/dayjs格式），日期格式化改用本地时间避免时区问题

frontend/src/views/production/ProductionPage.vue

@@ -3,7 +3,7 @@
     <!-- 查询条件区 -->
     <el-form :inline="true" label-width="90px" class="filter-bar" style="margin-bottom:12px;" :model="filters">
       <el-form-item label="日期">
-        <el-date-picker v-model="filters.dateRange" type="daterange" value-format="yyyy-MM-dd" range-separator="-" start-placeholder="开始日期" end-placeholder="结束日期" />
+        <el-date-picker v-model="filters.dateRange" type="daterange" value-format="YYYY-MM-DD" range-separator="-" start-placeholder="开始日期" end-placeholder="结束日期" />
       </el-form-item>
       <el-form-item label="车间">
         <el-select v-model="filters.workshopId" placeholder="请选择车间" clearable style="min-width:220px">
@@ -164,7 +164,8 @@ function resetFilters() {
   const end = new Date()
   const start = new Date()
   start.setDate(end.getDate() - 6)
-  filters.dateRange = [start.toISOString().split('T')[0], end.toISOString().split('T')[0]]
+  const fmt = (d: Date) => `${d.getFullYear()}-${String(d.getMonth()+1).padStart(2,'0')}-${String(d.getDate()).padStart(2,'0')}`
+  filters.dateRange = [fmt(start), fmt(end)]
   filters.workshopId = ''
   filters.machineId = ''
   filters.workerId = ''
@@ -176,8 +177,9 @@ function resetFilters() {
 // 初始化：加载筛选项与数据，设置默认日期为今天
 async function init() {
   // 默认今天
-  const today = new Date().toISOString().split('T')[0]
-  filters.dateRange = [today, today]
+  const today = new Date()
+  const fmt = (d: Date) => `${d.getFullYear()}-${String(d.getMonth()+1).padStart(2,'0')}-${String(d.getDate()).padStart(2,'0')}`
+  filters.dateRange = [fmt(today), fmt(today)]
   // 加载筛选项
   try {
     const [ws, mc, wr] = await Promise.all([