feat(pool,scheduling): 号池调度维度、配额冷却机制与管理后台重构

- 新增 scheduling_dimensions 模块，为每个 Key 计算多维调度状态(手动/冷却/熔断/成本/健康)
- 新增 quota_cooldown 模块，统一判定 Key 的有效冷却原因
- Pool 管理后台 API 扩展 Key 详情字段(调度状态/维度/配额/OAuth 信息)
- 前端 Pool 管理页面重写，支持调度状态展示、批量清理封禁 Key
- Handler 基类增加请求调度元数据采集，stream telemetry 增强
- 请求时间线组件增强，支持 attempted 候选展示
- Kiro OAuth 凭证导入解析改进
- 新增 usage 表 provider_key 索引迁移
- 补充调度维度、配额冷却、候选枚举等单元测试

Closes #197

Co-authored-by: AAEE86 <33052466+AAEE86@users.noreply.github.com>

frontend/src/features/providers/components/OAuthAccountDialog.vue

@@ -404,70 +404,19 @@
           class="flex flex-col gap-3 justify-center transition-opacity duration-150"
           :class="mode === 'import' ? 'opacity-100' : 'opacity-0 pointer-events-none'"
         >
-          <input
-            ref="fileInputRef"
-            type="file"
-            accept=".json,.txt"
-            multiple
-            class="hidden"
-            @change="handleFileSelect"
-          >
-
-          <!-- 拖拽模式 -->
-          <div
-            v-if="!showManualInput"
-            class="rounded-xl border-2 border-dashed transition-colors cursor-pointer"
-            :class="isDragging
-              ? 'border-primary bg-primary/5'
-              : 'border-border hover:border-muted-foreground/40'"
-            @click="fileInputRef?.click()"
-            @dragover.prevent="isDragging = true"
-            @dragleave.prevent="isDragging = false"
-            @drop.prevent="handleFileDrop"
-          >
-            <div class="flex flex-col items-center justify-center py-12 gap-2">
-              <div class="w-9 h-9 rounded-full bg-muted/60 flex items-center justify-center">
-                <Upload class="w-4 h-4 text-muted-foreground" />
-              </div>
-              <div class="text-center">
-                <p class="text-xs font-medium">
-                  拖入授权文件或点击选择
-                </p>
-                <p class="text-[11px] text-muted-foreground mt-0.5">
-                  支持 .json / .txt，可多选
-                </p>
-              </div>
-            </div>
-          </div>
-
-          <!-- 粘贴模式 -->
-          <Textarea
-            v-else
+          <JsonImportInput
             v-model="importText"
             :disabled="importing"
-            placeholder="粘贴 Refresh Token 或 JSON 内容"
-            class="min-h-[200px] text-xs font-mono break-all !rounded-xl"
-            spellcheck="false"
+            :reset-key="importInputResetKey"
+            drop-title="拖入授权文件或点击选择"
+            drop-hint="支持 .json / .txt，可多选"
+            manual-placeholder="粘贴 Refresh Token 或 JSON 内容"
+            paste-toggle-text="或手动粘贴 Refresh Token"
+            file-toggle-text="或选择 JSON 文件导入"
+            textarea-class="min-h-[200px] text-xs font-mono break-all !rounded-xl"
+            @error="handleImportInputError"
           />
 
-          <!-- 底部切换链接 -->
-          <div class="flex items-center justify-center pt-1">
-            <button
-              v-if="!showManualInput"
-              class="text-sm text-muted-foreground hover:text-foreground transition-colors"
-              @click="showManualInput = true"
-            >
-              或手动粘贴 Refresh Token
-            </button>
-            <button
-              v-else
-              class="text-sm text-muted-foreground hover:text-foreground transition-colors"
-              @click="showManualInput = false; importText = ''"
-            >
-              或选择 JSON 文件导入
-            </button>
-          </div>
-
           <div
             v-if="importTask"
             class="rounded-xl border border-border bg-muted/20 p-3 space-y-2"
@@ -554,7 +503,7 @@ import {
   ComboboxTrigger,
   ComboboxViewport,
 } from 'radix-vue'
-import { UserPlus, Copy, ExternalLink, Upload, Globe, AlertCircle, ShieldCheck, ChevronsUpDown, Check } from 'lucide-vue-next'
+import { UserPlus, Copy, ExternalLink, Globe, AlertCircle, ShieldCheck, ChevronsUpDown, Check } from 'lucide-vue-next'
 import { useToast } from '@/composables/useToast'
 import { useClipboard } from '@/composables/useClipboard'
 import { useTotp } from '@/composables/useTotp'
@@ -575,6 +524,7 @@ import type {
 } from '@/api/endpoints/provider_oauth'
 import ProxyNodeSelect from './ProxyNodeSelect.vue'
 import { useProxyNodesStore } from '@/stores/proxy-nodes'
+import JsonImportInput from '@/components/common/JsonImportInput.vue'
 
 const props = defineProps<{
   open: boolean
@@ -712,9 +662,7 @@ let countdownTimer: ReturnType<typeof setInterval> | null = null
 // 导入状态
 const importText = ref('')
 const importing = ref(false)
-const isDragging = ref(false)
-const showManualInput = ref(false)
-const fileInputRef = ref<HTMLInputElement | null>(null)
+const importInputResetKey = ref(0)
 const importTask = ref<OAuthBatchImportTaskStatusResponse | null>(null)
 let importPollTimer: ReturnType<typeof setTimeout> | null = null
 const importPolling = ref(false)
@@ -847,14 +795,10 @@ function resetForm() {
   importText.value = ''
   importing.value = false
   importTask.value = null
-  isDragging.value = false
-  showManualInput.value = false
+  importInputResetKey.value += 1
   proxyPopoverOpen.value = false
   selectedProxyNodeId.value = ''
   mode.value = 'oauth'
-  if (fileInputRef.value) {
-    fileInputRef.value.value = ''
-  }
 }
 
 function switchMode(newMode: DialogMode) {
@@ -978,81 +922,8 @@ function parseImportText(text: string): { refresh_token: string; name?: string }
   return { refresh_token: trimmed }
 }
 
-function readFileAsText(file: File): Promise<string> {
-  return new Promise((resolve, reject) => {
-    const reader = new FileReader()
-    reader.onload = (e) => {
-      const content = e.target?.result
-      if (typeof content === 'string') resolve(content)
-      else reject(new Error('读取失败'))
-    }
-    reader.onerror = () => reject(new Error('读取失败'))
-    reader.readAsText(file)
-  })
-}
-
-function isValidFileType(file: File): boolean {
-  return file.name.endsWith('.json') || file.name.endsWith('.txt')
-    || file.type === 'application/json' || file.type === 'text/plain'
-}
-
-/** 合并多个文件内容为统一的凭据文本（JSON 数组） */
-function mergeFileContents(contents: string[]): string {
-  const items: unknown[] = []
-  for (const raw of contents) {
-    const trimmed = raw.trim()
-    if (!trimmed) continue
-    try {
-      const parsed = JSON.parse(trimmed)
-      if (Array.isArray(parsed)) {
-        items.push(...parsed)
-      } else {
-        items.push(parsed)
-      }
-      continue
-    } catch {
-      // not JSON
-    }
-    // 按行拆分（纯 Token）
-    const lines = trimmed.split('\n').filter(l => l.trim() && !l.trim().startsWith('#'))
-    items.push(...lines.map(l => l.trim()))
-  }
-  if (items.length === 1) {
-    // 单条：保持原始格式
-    return typeof items[0] === 'string' ? items[0] : JSON.stringify(items[0], null, 2)
-  }
-  return JSON.stringify(items, null, 2)
-}
-
-async function readFiles(files: File[]) {
-  const validFiles = files.filter(isValidFileType)
-  if (validFiles.length === 0) {
-    showError('仅支持 .json 或 .txt 文件', '格式错误')
-    return
-  }
-  if (validFiles.length < files.length) {
-    showError(`已忽略 ${files.length - validFiles.length} 个不支持的文件`, '提示')
-  }
-  try {
-    const contents = await Promise.all(validFiles.map(readFileAsText))
-    const merged = validFiles.length === 1 ? contents[0] : mergeFileContents(contents)
-    importText.value = merged
-    showManualInput.value = true
-  } catch {
-    showError('文件读取失败', '错误')
-  }
-}
-
-function handleFileSelect(event: Event) {
-  const input = event.target as HTMLInputElement
-  const files = input.files
-  if (files && files.length > 0) readFiles(Array.from(files))
-}
-
-function handleFileDrop(event: DragEvent) {
-  isDragging.value = false
-  const files = event.dataTransfer?.files
-  if (files && files.length > 0) readFiles(Array.from(files))
+function handleImportInputError(payload: { message: string; title?: string }) {
+  showError(payload.message, payload.title)
 }
 
 async function handleImport() {