feat(test,quota,failover): 模型并发测试、统一配额读取器与故障转移取消支持

- 新增 QuotaReader 抽象层，统一 Codex/Kiro/Antigravity 配额解析逻辑，
  替换 pool/routes.py 中分散的配额构建函数
- 模型测试支持并发执行多候选，前端新增 useModelTest composable 统一
  ModelsTab 和 ModelMappingTab 的测试逻辑
- ModelTestDialog 增加结果概览摘要、超长结果折叠、端点列和新状态支持，
  删除已合并的 TestResultDialog
- FailoverEngine 新增客户端断开检测，支持取消剩余候选并标记记录
- 刷新配额改为分批执行，直连测试候选按可用性排序
- 修复 error 判断从 "error" in dict 改为 dict.get("error") 避免误判

frontend/src/composables/useModelTest.ts

@@ -0,0 +1,183 @@
+import { ref, onBeforeUnmount } from 'vue'
+import { isAxiosError } from 'axios'
+import { useToast } from './useToast'
+import {
+  testModelFailover,
+  type TestModelFailoverResponse,
+} from '@/api/endpoints/providers'
+import { requestTraceApi, type RequestTrace } from '@/api/requestTrace'
+import { parseApiError } from '@/utils/errorParser'
+
+export interface StartTestParams {
+  mode: 'global' | 'direct'
+  modelName: string
+  displayLabel: string
+  apiFormat?: string
+  endpointId?: string
+  message?: string
+  concurrency?: number
+  onSuccess?: (result: TestModelFailoverResponse) => void
+  /** Return `true` to indicate the failure has been handled; otherwise the composable sets `testResult`. */
+  onFailure?: (result: TestModelFailoverResponse) => boolean | void
+  /** Return `true` to indicate the error has been handled; otherwise a toast is shown and state is reset. */
+  onError?: (err: unknown) => boolean | void
+}
+
+export interface UseModelTestOptions {
+  providerId: () => string
+  pollInterval?: number
+}
+
+export function useModelTest(options: UseModelTestOptions) {
+  const { providerId, pollInterval = 800 } = options
+  const { success: showSuccess, error: showError } = useToast()
+
+  const testing = ref(false)
+  const testMode = ref<'global' | 'direct'>('global')
+  const testResult = ref<TestModelFailoverResponse | null>(null)
+  const testTrace = ref<RequestTrace | null>(null)
+  const requestId = ref<string | null>(null)
+  const dialogOpen = ref(false)
+
+  let tracePollTimer: ReturnType<typeof setInterval> | null = null
+  let tracePollToken = 0
+  let activeAbortController: AbortController | null = null
+
+  function buildTestRequestId(): string {
+    const randomUUID = globalThis.crypto?.randomUUID?.bind(globalThis.crypto)
+    if (randomUUID) {
+      return `provider-test-${randomUUID().replace(/-/g, '').slice(0, 20)}`
+    }
+    return `provider-test-${Date.now().toString(36)}${Math.random().toString(36).slice(2, 10)}`
+  }
+
+  async function pollTestTrace(reqId: string, token: number) {
+    try {
+      const trace = await requestTraceApi.getRequestTrace(reqId, { attemptedOnly: false })
+      if (tracePollToken !== token || requestId.value !== reqId) return
+      testTrace.value = trace
+    } catch (err: unknown) {
+      if (isAxiosError(err) && err.response?.status === 404) return
+    }
+  }
+
+  function stopPolling(opts: { clearState?: boolean } = {}) {
+    tracePollToken += 1
+    if (tracePollTimer) {
+      clearInterval(tracePollTimer)
+      tracePollTimer = null
+    }
+    if (opts.clearState !== false) {
+      requestId.value = null
+      testTrace.value = null
+    }
+  }
+
+  function startPolling(reqId: string) {
+    stopPolling()
+    requestId.value = reqId
+    testTrace.value = null
+    const token = ++tracePollToken
+    void pollTestTrace(reqId, token)
+    tracePollTimer = setInterval(() => {
+      void pollTestTrace(reqId, token)
+    }, pollInterval)
+  }
+
+  function abortActiveRequest() {
+    if (!activeAbortController) return
+    activeAbortController.abort()
+    activeAbortController = null
+  }
+
+  function isRequestCancelled(err: unknown): boolean {
+    if (isAxiosError(err)) {
+      return err.code === 'ERR_CANCELED'
+    }
+    return err instanceof DOMException && err.name === 'AbortError'
+  }
+
+  function resetState() {
+    abortActiveRequest()
+    stopPolling()
+    dialogOpen.value = false
+    testResult.value = null
+  }
+
+  async function startTest(params: StartTestParams) {
+    abortActiveRequest()
+    testing.value = true
+    testMode.value = params.mode
+    dialogOpen.value = true
+    testResult.value = null
+
+    const abortController = new AbortController()
+    activeAbortController = abortController
+    const reqId = buildTestRequestId()
+    startPolling(reqId)
+
+    try {
+      const result = await testModelFailover({
+        provider_id: providerId(),
+        mode: params.mode,
+        model_name: params.modelName,
+        api_format: params.apiFormat,
+        endpoint_id: params.endpointId,
+        message: params.message ?? 'hello',
+        request_id: reqId,
+        concurrency: params.concurrency,
+      }, {
+        signal: abortController.signal,
+      })
+
+      if (result.success) {
+        const successAttempt = result.attempts.find(a => a.status === 'success')
+        const latency = successAttempt?.latency_ms != null ? ` (${successAttempt.latency_ms}ms)` : ''
+        const mapped = successAttempt?.effective_model && successAttempt.effective_model !== params.modelName
+          ? ` -> ${successAttempt.effective_model}`
+          : ''
+        params.onSuccess?.(result)
+        showSuccess(`${params.displayLabel}${mapped} 测试成功${latency}`)
+        resetState()
+        return
+      }
+
+      stopPolling({ clearState: false })
+      const handled = params.onFailure?.(result)
+      if (!handled) {
+        testResult.value = result
+      }
+    } catch (err: unknown) {
+      if (isRequestCancelled(err)) {
+        return
+      }
+      stopPolling()
+      const handled = params.onError?.(err)
+      if (!handled) {
+        showError(`模型测试失败: ${parseApiError(err, '测试请求失败')}`)
+        resetState()
+      }
+    } finally {
+      if (activeAbortController === abortController) {
+        activeAbortController = null
+      }
+      testing.value = false
+    }
+  }
+
+  onBeforeUnmount(() => {
+    resetState()
+  })
+
+  return {
+    testing,
+    testMode,
+    testResult,
+    testTrace,
+    requestId,
+    dialogOpen,
+    startTest,
+    resetState,
+    stopPolling,
+  }
+}