feat(frontend): 回测两页补实例档案下拉——回测/模拟/实盘三入口都能选档案(用户验收追问);CTA页instance预填提取applyInstance复用(跳转带入+下拉选择统一selectedInstanceId);组合页加下拉+预填(策略/max_pool/benchmark/pool)+getInstances加载;提交instance_id改用selectedInstanceId;build绿 [vps]

frontend/src/views/backtest/PortfolioBacktest.vue

@@ -6,6 +6,7 @@ import type { EChartsCoreOption } from 'echarts'
 import { useChart } from '@/composables/useChart'
 import { darkTitle, darkTooltip, darkGrid, darkAxis } from '@/utils/echartsDark'
 import { getTaskParams } from '@/api/backtest'
+import { getInstances } from '@/api/strategy'
 import { apiClient } from '@/api/client'
 import { disableFutureDate } from '@/utils/dates'
 import { INTERVAL_OPTIONS } from '@/constants/intervals'
@@ -51,6 +52,8 @@ function loadDateRange(): { start: string; end: string } {
   return { start: f(start), end: f(end) }
 }
 const dr = loadDateRange()
+// §12.6 选档案（跳转带入或页面下拉），提交带 instance_id 回写四格
+const selectedInstanceId = ref<number | null>(null)
 const form = reactive({
   pool: 'hs300_subset',
   strategy: 'all_weather',
@@ -371,7 +374,7 @@ async function onSubmit(): Promise<void> {
       min_commission: Number(form.min_commission),
       slippage: Number(form.slippage),
       interval: form.interval,
-      instance_id: route.query.instance && !Array.isArray(route.query.instance) ? Number(route.query.instance) : null,
+      instance_id: selectedInstanceId.value,
     })
     ElMessage.success('回测已提交,后台运行中')
     router.push('/backtest/history') // 跳任务中心(历史任务页)看进度/结果
@@ -383,7 +386,7 @@ async function onSubmit(): Promise<void> {
 
 const fromTaskId = computed(() => (route.query.from_task as string) || '')
 
-onMounted(() => {
+onMounted(async () => {
   if (viewTaskId.value) {
     loadResult(viewTaskId.value)
   } else if (route.query.strategy) {
@@ -395,9 +398,25 @@ onMounted(() => {
   }
   // §12.6 从策略库档案发起：按档案参数预填（max_pool/benchmark 等）
   const instQ = route.query.instance
-  if (instQ && !Array.isArray(instQ)) void prefillFromInstance(Number(instQ))
+  if (instQ && !Array.isArray(instQ)) {
+    selectedInstanceId.value = Number(instQ)
+    void prefillFromInstance(Number(instQ))
+  }
+  try {
+    instanceOptions.value = await getInstances()
+  } catch {
+    /* 档案下拉失败不阻塞 */
+  }
 })
 
+// §12.6 选档案：跳转带入或页面下拉选择，提交带 instance_id 回写四格
+const instanceOptions = ref<{ id: number; name: string; code_file: string; interval: string }[]>([])
+
+function onPickInstance(id: number | null): void {
+  selectedInstanceId.value = id
+  if (id != null) void prefillFromInstance(id)
+}
+
 async function prefillFromInstance(instId: number): Promise<void> {
   try {
     const { data } = await apiClient.get<{
@@ -461,6 +480,20 @@ function fmtNum(v: number | null | undefined, digits = 2): string {
       <el-card class="blk" shadow="never">
         <template #header><span class="section-title">策略与选股</span></template>
         <el-form :model="form" label-width="120px">
+          <el-form-item label="实例档案">
+            <el-select
+              :model-value="selectedInstanceId" clearable filterable
+              placeholder="选档案带出参数并回写结果（可选）；不选=自由回测"
+              style="width: 420px"
+              @update:model-value="onPickInstance"
+            >
+              <el-option
+                v-for="i in instanceOptions" :key="i.id" :value="i.id"
+                :label="`${i.name}（${i.code_file || '—'}·${i.interval}）`"
+              />
+            </el-select>
+            <span v-if="selectedInstanceId != null" class="muted form-hint">已绑档案 #{{ selectedInstanceId }}，完成后回写档案</span>
+          </el-form-item>
           <el-form-item label="标的池">
             <el-select v-model="form.pool" style="width: 320px">
               <el-option v-for="opt in poolOptions" :key="opt.value" :label="opt.label" :value="opt.value" />