feat: add client affinity toggle to create account modal

The client affinity setting was only available when editing an account.
Now it's also available during account creation for all Anthropic
platform types (OAuth, Setup Token, API Key).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/components/account/CreateAccountModal.vue

@@ -1410,6 +1410,36 @@
         </div>
       </div>
 
+      <!-- Client Affinity (Anthropic accounts only) -->
+      <div
+        v-if="form.platform === 'anthropic'"
+        class="border-t border-gray-200 pt-4 dark:border-dark-600"
+      >
+        <div class="flex items-center justify-between">
+          <div>
+            <label class="input-label mb-0">{{ t('admin.accounts.quotaControl.clientAffinity.label') }}</label>
+            <p class="mt-1 text-xs text-gray-500 dark:text-gray-400">
+              {{ t('admin.accounts.quotaControl.clientAffinity.hint') }}
+            </p>
+          </div>
+          <button
+            type="button"
+            @click="clientAffinityEnabled = !clientAffinityEnabled"
+            :class="[
+              'relative inline-flex h-6 w-11 flex-shrink-0 cursor-pointer rounded-full border-2 border-transparent transition-colors duration-200 ease-in-out focus:outline-none focus:ring-2 focus:ring-primary-500 focus:ring-offset-2',
+              clientAffinityEnabled ? 'bg-primary-600' : 'bg-gray-200 dark:bg-dark-600'
+            ]"
+          >
+            <span
+              :class="[
+                'pointer-events-none inline-block h-5 w-5 transform rounded-full bg-white shadow ring-0 transition duration-200 ease-in-out',
+                clientAffinityEnabled ? 'translate-x-5' : 'translate-x-0'
+              ]"
+            />
+          </button>
+        </div>
+      </div>
+
       <!-- Quota Control Section (Anthropic OAuth/SetupToken only) -->
       <div
         v-if="form.platform === 'anthropic' && accountCategory === 'oauth-based'"
@@ -2515,6 +2545,9 @@ const antigravityMixedChannelConfirmed = ref(false)
 const showAdvancedOAuth = ref(false)
 const showGeminiHelpDialog = ref(false)
 
+// Client affinity (all Anthropic accounts)
+const clientAffinityEnabled = ref(false)
+
 // Quota control state (Anthropic OAuth/SetupToken only)
 const windowCostEnabled = ref(false)
 const windowCostLimit = ref<number | null>(null)
@@ -3140,6 +3173,7 @@ const resetForm = () => {
   editQuotaLimit.value = null
   editQuotaDailyLimit.value = null
   editQuotaWeeklyLimit.value = null
+  clientAffinityEnabled.value = false
   modelMappings.value = []
   modelRestrictionMode.value = 'whitelist'
   allowedModels.value = [...claudeModels] // Default fill related models
@@ -3243,10 +3277,20 @@ const buildAnthropicExtra = (base?: Record<string, unknown>): Record<string, unk
   } else {
     delete extra.anthropic_passthrough
   }
+  applyClientAffinity(extra)
 
   return Object.keys(extra).length > 0 ? extra : undefined
 }
 
+/** 将客户端亲和设置写入 extra（Anthropic 全类型通用） */
+const applyClientAffinity = (extra: Record<string, unknown>) => {
+  if (clientAffinityEnabled.value) {
+    extra.client_affinity_enabled = true
+  } else {
+    delete extra.client_affinity_enabled
+  }
+}
+
 const buildSoraExtra = (
   base?: Record<string, unknown>,
   linkedOpenAIAccountId?: string | number
@@ -4143,6 +4187,9 @@ const handleAnthropicExchange = async (authCode: string) => {
       extra.cache_ttl_override_target = cacheTTLOverrideTarget.value
     }
 
+    // Add client affinity setting
+    applyClientAffinity(extra)
+
     const credentials: Record<string, unknown> = { ...tokenInfo }
     applyInterceptWarmup(credentials, interceptWarmupRequests.value, 'create')
     await createAccountAndFinish(form.platform, addMethod.value as AccountType, credentials, extra)