feat(billing-probe): optionally sync account rate from upstream declared rate

Successful upstream billing probes already persist the upstream-declared
rate as a display-only snapshot. Add a per-account opt-in that writes
that declared rate back to the account's rate_multiplier, so the account
cost basis follows upstream repricing automatically instead of drifting
until an operator notices.

- new per-account flag upstream_billing_rate_sync_enabled stored next to
  the probe flag in account extra: enabling sync force-enables the
  probe, disabling the probe cascades sync off, and eligibility follows
  IsUpstreamBillingProbeIdentity (tightened from any non-empty platform
  to an explicit whitelist of the five supported API-key platforms so
  future platforms do not silently inherit probe/sync semantics)
- only a successful probe whose declared rate survives validation
  (finite, within bounds, not rounded to zero at the rate_multiplier
  decimal(10,4) scale) writes back; failed/unsupported/invalid probes
  leave rate_multiplier unchanged
- the writeback rides the existing snapshot CAS transaction:
  UpdateUpstreamBillingProbeSnapshot takes an optional rateMultiplier
  and applies it atomically with the snapshot under the same
  identity/snapshot compare-and-swap, so a probe result observed on a
  stale account cannot clobber a concurrent admin edit
- admin edit goes through UpdateWithAccountBillingSettings, which
  applies the form without overwriting a rate that a probe synchronized
  after the edit form was loaded (nil rateMultiplier = not edited);
  once sync is enabled the edit form shows the rate as managed
- bulk update rejects a manual rate_multiplier change when any target
  account has rate sync enabled (whole batch fails with a dedicated
  error so partial writes cannot bypass the sync ownership)
- frontend: sync toggle with hints in the edit modal (probe/sync
  enable/disable coupling enforced in the form), synced-rate tooltip on
  the rate cell, bulk edit modal warns and blocks rate edits that hit
  sync-enabled accounts; en/zh copy updated
- tests: service unit tests for sync gating/validation/cascade, sqlmock
  repo tests for the extended CAS, real-PostgreSQL integration tests
  (rate written only for successful+enabled accounts, manual rate
  protected after sync disabled, admin edit preserved across concurrent
  probe sync), handler/API contract updates, frontend specs for modal
  coupling, bulk rejection and rate cell

frontend/src/components/account/BulkEditAccountModal.vue

@@ -750,6 +750,14 @@
             aria-labelledby="bulk-edit-rate-multiplier-label"
           />
           <p class="input-hint">{{ t('admin.accounts.billingRateMultiplierHint') }}</p>
+          <p
+            v-if="enableRateMultiplier"
+            class="mt-2 flex items-start gap-1 text-xs text-amber-700 dark:text-amber-300"
+            data-testid="bulk-rate-sync-warning"
+          >
+            <Icon name="exclamationTriangle" size="xs" class="mt-0.5 flex-shrink-0" />
+            <span>{{ t('admin.accounts.bulkEdit.rateSyncWarning') }}</span>
+          </p>
         </div>
       </div>
 
@@ -1985,6 +1993,10 @@ const submitBulkUpdate = async (baseUpdates: Record<string, unknown>) => {
       pendingUpdatesForConfirm.value = baseUpdates
       mixedChannelWarningMessage.value = error.message
       showMixedChannelWarning.value = true
+    } else if (error.reason === 'UPSTREAM_BILLING_RATE_SYNC_BULK_CONFLICT') {
+      appStore.showError(t('admin.accounts.bulkEdit.rateSyncConflict', {
+        count: error.metadata?.count ?? 1
+      }))
     } else {
       appStore.showError(error.message || t('admin.accounts.bulkEdit.failed'))
       console.error('Error bulk updating accounts:', error)

frontend/src/components/account/EditAccountModal.vue

@@ -1441,8 +1441,43 @@
         </div>
         <div>
           <label class="input-label">{{ t('admin.accounts.billingRateMultiplier') }}</label>
-          <input v-model.number="form.rate_multiplier" type="number" min="0" step="0.001" class="input" />
-          <p class="input-hint">{{ t('admin.accounts.billingRateMultiplierHint') }}</p>
+          <input
+            v-model.number="form.rate_multiplier"
+            type="number"
+            min="0"
+            step="0.001"
+            class="input disabled:cursor-not-allowed disabled:opacity-60"
+            data-testid="account-rate-multiplier"
+            :disabled="upstreamBillingRateSyncEnabled"
+          />
+          <p class="input-hint">
+            {{
+              t(
+                upstreamBillingRateSyncEnabled
+                  ? 'admin.accounts.upstreamBilling.syncRateManagedHint'
+                  : 'admin.accounts.billingRateMultiplierHint'
+              )
+            }}
+          </p>
+          <div
+            v-if="account?.type === 'apikey'"
+            class="mt-3 flex items-center justify-between gap-3"
+          >
+            <div class="min-w-0">
+              <p class="text-xs font-medium text-gray-700 dark:text-gray-200">
+                {{ t('admin.accounts.upstreamBilling.syncRate') }}
+              </p>
+              <p class="mt-1 text-xs text-gray-500 dark:text-gray-400">
+                {{ t('admin.accounts.upstreamBilling.syncRateHint') }}
+              </p>
+            </div>
+            <Toggle
+              :model-value="upstreamBillingRateSyncEnabled"
+              data-testid="upstream-billing-rate-sync"
+              :aria-label="t('admin.accounts.upstreamBilling.syncRate')"
+              @update:model-value="handleUpstreamBillingRateSyncChange"
+            />
+          </div>
         </div>
       </div>
       <div class="border-t border-gray-200 pt-4 dark:border-dark-600">
@@ -1660,9 +1695,10 @@
           </p>
         </div>
         <Toggle
-          v-model="upstreamBillingAutoProbeEnabled"
+          :model-value="upstreamBillingAutoProbeEnabled"
           data-testid="upstream-billing-auto-probe"
           :aria-label="t('admin.accounts.upstreamBilling.autoProbe')"
+          @update:model-value="handleUpstreamBillingAutoProbeChange"
         />
       </div>
 
@@ -2822,6 +2858,7 @@ const autoPause7dThreshold = ref<number | null>(null)
 const autoPause5hDisabled = ref(false)
 const autoPause7dDisabled = ref(false)
 const upstreamBillingAutoProbeEnabled = ref(false)
+const upstreamBillingRateSyncEnabled = ref(false)
 const mixedScheduling = ref(false) // For antigravity accounts: enable mixed scheduling
 const allowOverages = ref(false) // For antigravity accounts: enable AI Credits overages
 const antigravityProjectId = ref('')
@@ -3191,6 +3228,20 @@ const form = reactive({
   expires_at: null as number | null
 })
 
+const handleUpstreamBillingRateSyncChange = (enabled: boolean) => {
+  upstreamBillingRateSyncEnabled.value = enabled
+  if (enabled) {
+    upstreamBillingAutoProbeEnabled.value = true
+  }
+}
+
+const handleUpstreamBillingAutoProbeChange = (enabled: boolean) => {
+  upstreamBillingAutoProbeEnabled.value = enabled
+  if (!enabled) {
+    upstreamBillingRateSyncEnabled.value = false
+  }
+}
+
 const statusOptions = computed(() => {
   const options = [
     { value: 'active', label: t('common.active') },
@@ -3306,6 +3357,8 @@ const syncFormFromAccount = (newAccount: Account | null) => {
 	autoPause5hDisabled.value = extra?.auto_pause_5h_disabled === true
 	autoPause7dDisabled.value = extra?.auto_pause_7d_disabled === true
 	upstreamBillingAutoProbeEnabled.value = extra?.upstream_billing_probe_enabled === true
+  upstreamBillingRateSyncEnabled.value =
+    upstreamBillingAutoProbeEnabled.value && extra?.upstream_billing_rate_sync_enabled === true
 
   // Load OpenAI passthrough toggle (OpenAI OAuth/SetupToken/API Key)
   openaiPassthroughEnabled.value = false
@@ -4086,6 +4139,13 @@ const handleSubmit = async () => {
       updatePayload.load_factor = 0
     }
     updatePayload.auto_pause_on_expired = autoPauseOnExpired.value
+    if (props.account.type === 'apikey') {
+      updatePayload.upstream_billing_probe_enabled = upstreamBillingAutoProbeEnabled.value
+      updatePayload.upstream_billing_rate_sync_enabled = upstreamBillingRateSyncEnabled.value
+      if (upstreamBillingRateSyncEnabled.value) {
+        delete updatePayload.rate_multiplier
+      }
+    }
 
     // For apikey type, handle credentials update
     if (props.account.type === 'apikey') {
@@ -4651,7 +4711,8 @@ const handleSubmit = async () => {
       // 上游倍率自动探测对全部 API-key 平台开放（sub2api 上游即可应答），
       // Bedrock 凭证无静态 Key 不参与。
       if (props.account.type === 'apikey') {
-        newExtra.upstream_billing_probe_enabled = upstreamBillingAutoProbeEnabled.value
+        delete newExtra.upstream_billing_probe_enabled
+        delete newExtra.upstream_billing_rate_sync_enabled
       }
       // Total quota
       if (editQuotaLimit.value != null && editQuotaLimit.value > 0) {

frontend/src/components/account/UpstreamBillingRateCell.vue

@@ -88,6 +88,7 @@ import { computed } from 'vue'
 import { useI18n } from 'vue-i18n'
 import HelpTooltip from '@/components/common/HelpTooltip.vue'
 import Icon from '@/components/icons/Icon.vue'
+import { formatMultiplier } from '@/utils/formatters'
 import type { Account, UpstreamBillingProbeSnapshot } from '@/types'
 
 const props = withDefaults(defineProps<{
@@ -191,7 +192,7 @@ const elapsedSinceLastSuccess = computed(() => {
 const effectiveRate = computed(() => {
   if (!validTimestamps.value || stale.value || !['ok', 'failed'].includes(snapshot.value?.status ?? '')) return '-'
   const value = currentEffectiveRate.value
-  return value == null ? '-' : `${Number(value.toPrecision(12))}x`
+  return value == null ? '-' : `${formatMultiplier(value)}x`
 })
 const statusLabel = computed(() => {
   if (!snapshot.value) return t('admin.accounts.upstreamBilling.notProbed')

frontend/src/components/account/__tests__/BulkEditAccountModal.spec.ts

@@ -4,9 +4,13 @@ import BulkEditAccountModal from '../BulkEditAccountModal.vue'
 import ModelWhitelistSelector from '../ModelWhitelistSelector.vue'
 import { adminAPI } from '@/api/admin'
 
+const { showError } = vi.hoisted(() => ({
+  showError: vi.fn()
+}))
+
 vi.mock('@/stores/app', () => ({
   useAppStore: () => ({
-    showError: vi.fn(),
+    showError,
     showSuccess: vi.fn(),
     showInfo: vi.fn()
   })
@@ -77,6 +81,7 @@ describe('BulkEditAccountModal', () => {
   beforeEach(() => {
     vi.mocked(adminAPI.accounts.bulkUpdate).mockReset()
     vi.mocked(adminAPI.accounts.checkMixedChannelRisk).mockReset()
+    showError.mockReset()
 
     vi.mocked(adminAPI.accounts.bulkUpdate).mockResolvedValue({
       success: 2,
@@ -88,6 +93,33 @@ describe('BulkEditAccountModal', () => {
     } as any)
   })
 
+  it('批量修改倍率时提示自动同步账号需要先关闭同步', async () => {
+    const wrapper = mountModal()
+
+    expect(wrapper.find('[data-testid="bulk-rate-sync-warning"]').exists()).toBe(false)
+    await wrapper.get('#bulk-edit-rate-multiplier-enabled').setValue(true)
+
+    expect(wrapper.get('[data-testid="bulk-rate-sync-warning"]').text()).toContain(
+      'admin.accounts.bulkEdit.rateSyncWarning'
+    )
+  })
+
+  it('后端拒绝修改同步账号倍率时展示专用错误', async () => {
+    vi.mocked(adminAPI.accounts.bulkUpdate).mockRejectedValueOnce({
+      status: 409,
+      reason: 'UPSTREAM_BILLING_RATE_SYNC_BULK_CONFLICT',
+      metadata: { count: '2' },
+      message: 'conflict'
+    })
+    const wrapper = mountModal()
+
+    await wrapper.get('#bulk-edit-rate-multiplier-enabled').setValue(true)
+    await wrapper.get('#bulk-edit-account-form').trigger('submit.prevent')
+    await flushPromises()
+
+    expect(showError).toHaveBeenCalledWith('admin.accounts.bulkEdit.rateSyncConflict')
+  })
+
   it('antigravity 白名单包含 Gemini 图片模型且过滤掉普通 GPT 模型', async () => {
     const wrapper = mountModal()
     const selector = wrapper.findComponent(ModelWhitelistSelector)

frontend/src/components/account/__tests__/EditAccountModal.spec.ts

@@ -654,7 +654,10 @@ describe('EditAccountModal', () => {
     await wrapper.get('form#edit-account-form').trigger('submit.prevent')
 
     expect(updateAccountMock).toHaveBeenCalledTimes(1)
-    expect(updateAccountMock.mock.calls[0]?.[1]?.extra?.upstream_billing_probe_enabled).toBe(true)
+    expect(updateAccountMock.mock.calls[0]?.[1]?.upstream_billing_probe_enabled).toBe(true)
+    expect(updateAccountMock.mock.calls[0]?.[1]?.extra).not.toHaveProperty(
+      'upstream_billing_probe_enabled'
+    )
   })
 
   it('exposes the upstream billing auto-probe toggle for non-OpenAI API-key accounts', async () => {
@@ -676,7 +679,92 @@ describe('EditAccountModal', () => {
     await wrapper.get('form#edit-account-form').trigger('submit.prevent')
 
     expect(updateAccountMock).toHaveBeenCalledTimes(1)
-    expect(updateAccountMock.mock.calls[0]?.[1]?.extra?.upstream_billing_probe_enabled).toBe(true)
+    expect(updateAccountMock.mock.calls[0]?.[1]?.upstream_billing_probe_enabled).toBe(true)
+  })
+
+  it('enabling rate sync also enables probing and stops submitting a manual rate', async () => {
+    const account = buildAccount()
+    updateAccountMock.mockReset()
+    checkMixedChannelRiskMock.mockReset()
+    checkMixedChannelRiskMock.mockResolvedValue({ has_risk: false })
+    updateAccountMock.mockResolvedValue(account)
+
+    const wrapper = mountModal(account)
+    const syncToggle = wrapper.get('[data-testid="upstream-billing-rate-sync"]')
+    const probeToggle = wrapper.get('[data-testid="upstream-billing-auto-probe"]')
+    const rateInput = wrapper.get<HTMLInputElement>('[data-testid="account-rate-multiplier"]')
+    expect(syncToggle.attributes('aria-checked')).toBe('false')
+    expect(probeToggle.attributes('aria-checked')).toBe('false')
+    expect(rateInput.element.disabled).toBe(false)
+    expect(wrapper.text()).toContain('admin.accounts.billingRateMultiplierHint')
+    expect(wrapper.text()).not.toContain('admin.accounts.upstreamBilling.syncRateManagedHint')
+
+    await syncToggle.trigger('click')
+    expect(syncToggle.attributes('aria-checked')).toBe('true')
+    expect(probeToggle.attributes('aria-checked')).toBe('true')
+    expect(rateInput.element.disabled).toBe(true)
+    expect(wrapper.text()).toContain('admin.accounts.upstreamBilling.syncRateManagedHint')
+    expect(wrapper.text()).not.toContain('admin.accounts.billingRateMultiplierHint')
+    await wrapper.get('form#edit-account-form').trigger('submit.prevent')
+
+    const payload = updateAccountMock.mock.calls[0]?.[1]
+    expect(payload?.upstream_billing_probe_enabled).toBe(true)
+    expect(payload?.upstream_billing_rate_sync_enabled).toBe(true)
+    expect(payload).not.toHaveProperty('rate_multiplier')
+  })
+
+  it('disabling probing also disables rate sync and restores manual rate editing', async () => {
+    const account = buildAccount()
+    account.extra = {
+      upstream_billing_probe_enabled: true,
+      upstream_billing_rate_sync_enabled: true
+    }
+    updateAccountMock.mockReset()
+    checkMixedChannelRiskMock.mockReset()
+    checkMixedChannelRiskMock.mockResolvedValue({ has_risk: false })
+    updateAccountMock.mockResolvedValue(account)
+
+    const wrapper = mountModal(account)
+    const syncToggle = wrapper.get('[data-testid="upstream-billing-rate-sync"]')
+    const probeToggle = wrapper.get('[data-testid="upstream-billing-auto-probe"]')
+    const rateInput = wrapper.get<HTMLInputElement>('[data-testid="account-rate-multiplier"]')
+    expect(syncToggle.attributes('aria-checked')).toBe('true')
+    expect(rateInput.element.disabled).toBe(true)
+
+    await probeToggle.trigger('click')
+    expect(probeToggle.attributes('aria-checked')).toBe('false')
+    expect(syncToggle.attributes('aria-checked')).toBe('false')
+    expect(rateInput.element.disabled).toBe(false)
+    await wrapper.get('form#edit-account-form').trigger('submit.prevent')
+
+    const payload = updateAccountMock.mock.calls[0]?.[1]
+    expect(payload?.upstream_billing_probe_enabled).toBe(false)
+    expect(payload?.upstream_billing_rate_sync_enabled).toBe(false)
+    expect(payload?.rate_multiplier).toBe(1)
+  })
+
+  it('disabling only rate sync keeps automatic probing enabled', async () => {
+    const account = buildAccount()
+    account.extra = {
+      upstream_billing_probe_enabled: true,
+      upstream_billing_rate_sync_enabled: true
+    }
+    updateAccountMock.mockReset()
+    checkMixedChannelRiskMock.mockReset()
+    checkMixedChannelRiskMock.mockResolvedValue({ has_risk: false })
+    updateAccountMock.mockResolvedValue(account)
+
+    const wrapper = mountModal(account)
+    await wrapper.get('[data-testid="upstream-billing-rate-sync"]').trigger('click')
+    expect(wrapper.get('[data-testid="upstream-billing-auto-probe"]').attributes('aria-checked')).toBe(
+      'true'
+    )
+    await wrapper.get('form#edit-account-form').trigger('submit.prevent')
+
+    const payload = updateAccountMock.mock.calls[0]?.[1]
+    expect(payload?.upstream_billing_probe_enabled).toBe(true)
+    expect(payload?.upstream_billing_rate_sync_enabled).toBe(false)
+    expect(payload?.rate_multiplier).toBe(1)
   })
 
   it('clears OpenAI APIKey Responses override when set back to auto', async () => {

frontend/src/components/account/__tests__/UpstreamBillingRateCell.spec.ts

@@ -88,11 +88,11 @@ describe('UpstreamBillingRateCell', () => {
       }
     })
 
-    expect(wrapper.text()).toContain('0.6x')
+    expect(wrapper.text()).toContain('0.60x')
     await wrapper.setProps({ now: Date.parse('2026-07-13T01:00:00Z') })
-    expect(wrapper.text()).toContain('0.9x')
+    expect(wrapper.text()).toContain('0.90x')
     await wrapper.setProps({ now: Date.parse('2026-07-13T10:00:00Z') })
-    expect(wrapper.text()).toContain('0.6x')
+    expect(wrapper.text()).toContain('0.60x')
     expect(wrapper.text()).not.toContain('admin.accounts.upstreamBilling.latest')
     expect(wrapper.get('[data-testid="upstream-billing-probe"]').text()).toBe('')
     expect(wrapper.get('[data-testid="upstream-billing-probe"]').attributes('aria-label')).toBe(
@@ -132,11 +132,11 @@ describe('UpstreamBillingRateCell', () => {
         }
       })
     })
-    expect(wrapper.text()).toContain('0.6x')
+    expect(wrapper.text()).toContain('0.60x')
     expect(wrapper.text()).toContain('admin.accounts.upstreamBilling.failed')
 
     await wrapper.setProps({ now: Date.parse('2026-07-13T01:00:00Z') })
-    expect(wrapper.text()).toContain('0.9x')
+    expect(wrapper.text()).toContain('0.90x')
     expect(wrapper.text()).not.toContain('admin.accounts.upstreamBilling.stale')
 
     await wrapper.setProps({ now: Date.parse('2026-07-13T01:00:00.001Z') })
@@ -312,7 +312,7 @@ describe('UpstreamBillingRateCell', () => {
     await wrapper.setProps({ account: malformedAccount({}, { received_at: 'not-a-time' }) })
     expect(wrapper.get('[data-testid="upstream-billing-rate"]').text()).toBe('admin.accounts.upstreamBilling.stale')
     await wrapper.setProps({ account: malformedAccount({}, { received_at: '2026-07-13T00:31:00Z' }) })
-    expect(wrapper.get('[data-testid="upstream-billing-rate"]').text()).toBe('0.6x')
+    expect(wrapper.get('[data-testid="upstream-billing-rate"]').text()).toBe('0.60x')
     await wrapper.setProps({ account: malformedAccount({}, { received_at: '2026-07-13T00:36:00Z' }) })
     expect(wrapper.get('[data-testid="upstream-billing-rate"]').text()).toBe('admin.accounts.upstreamBilling.stale')
     await wrapper.setProps({ account: malformedAccount({}, { fresh_until: '2026-07-12T23:59:00Z' }) })