feat: 手动代理节点支持、系统默认代理与跨格式流式 usage 提取

代理节点:
- 支持手动添加代理节点(HTTP/HTTPS/SOCKS5)，含地址、认证信息和区域标签
- 新增手动节点的 CRUD API 和前端管理界面
- 提供商代理配置从 URL 字符串迁移至代理节点选择器(proxy_node_id)
- 新增系统默认代理节点设置，未单独配置代理的提供商自动回退使用
- 删除节点时自动清除系统默认代理引用并失效缓存
- 健康检查跳过手动节点(无心跳，始终在线)

流式处理:
- CLI handler 跨格式转换时委托基类解析 Provider 原始事件的 usage
- StreamProcessor 新增 _extract_usage_from_converted_event 从转换后事件补充提取 usage
- 支持 Claude/OpenAI/OpenAI Responses/Gemini 多种 usage 格式

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

@@ -53,7 +53,7 @@
             v-for="(group, groupIndex) in fieldGroups"
             :key="groupIndex"
           >
-            <!-- 可折叠的分组（如代理配置） -->
+            <!-- 可折叠的分组（代理配置 - 代理节点选择） -->
             <div
               v-if="group.collapsible && group.hasToggle && group.toggleKey"
               class="space-y-2"
@@ -65,50 +65,22 @@
                   <span class="text-xs text-muted-foreground">启用代理</span>
                   <Switch
                     :model-value="formData[group.toggleKey] || false"
-                    @update:model-value="formData[group.toggleKey] = $event"
+                    @update:model-value="handleProxyToggle(group.toggleKey, $event)"
                   />
                 </div>
               </div>
 
-              <!-- 展开内容（卡片） -->
+              <!-- 展开内容（卡片）- 代理节点选择 -->
               <div
                 v-if="formData[group.toggleKey]"
                 class="rounded-lg border border-border bg-muted/30 px-4 py-3"
               >
-                <!-- 横向排列的字段：代理地址占更多空间 -->
-                <div class="flex gap-3">
-                  <div
-                    v-for="(field, fieldIndex) in group.fields"
-                    :key="field.key"
-                    class="space-y-1"
-                    :class="fieldIndex === 0 ? 'flex-[2]' : 'flex-1'"
-                  >
-                    <Label class="text-xs text-muted-foreground">
-                      {{ field.label }}
-                    </Label>
-
-                    <!-- 文本输入 -->
-                    <Input
-                      v-if="field.type === 'text'"
-                      v-model="formData[field.key]"
-                      :placeholder="field.sensitive ? (sensitivePlaceholders[field.key] || field.placeholder) : field.placeholder"
-                      :masked="field.sensitive"
-                      disable-autofill
-                      class="h-8 text-sm"
-                      @update:model-value="handleFieldChange(field.key, $event)"
-                    />
-
-                    <!-- 密码/敏感输入 -->
-                    <Input
-                      v-else-if="field.type === 'password'"
-                      v-model="formData[field.key]"
-                      :placeholder="sensitivePlaceholders[field.key] || field.placeholder"
-                      masked
-                      class="h-8 text-sm"
-                      @update:model-value="handleFieldChange(field.key, $event)"
-                    />
-                  </div>
-                </div>
+                <ProxyNodeSelect
+                  ref="proxyNodeSelectRef"
+                  :model-value="formData.proxy_node_id || ''"
+                  trigger-class="h-8"
+                  @update:model-value="(v: string) => { formData.proxy_node_id = v; handleFieldChange('proxy_node_id', v) }"
+                />
               </div>
             </div>
 
@@ -304,6 +276,8 @@ import {
   type AuthTemplate,
   type AuthTemplateFieldGroup,
 } from '../auth-templates'
+import ProxyNodeSelect from './ProxyNodeSelect.vue'
+import { useProxyNodesStore } from '@/stores/proxy-nodes'
 
 const props = defineProps<{
   open: boolean
@@ -322,6 +296,16 @@ const SENSITIVE_FIELDS = ['api_key', 'password', 'session_token', 'session_cooki
 
 const { success: showSuccess, error: showError } = useToast()
 const { confirmDanger } = useConfirm()
+const proxyNodeSelectRef = ref<InstanceType<typeof ProxyNodeSelect> | null>(null)
+const proxyNodesStore = useProxyNodesStore()
+
+/** 启用代理时加载节点列表（直接调用 store，避免 ref 未挂载时静默失败） */
+function handleProxyToggle(toggleKey: string, value: boolean) {
+  formData.value[toggleKey] = value
+  if (value) {
+    proxyNodesStore.ensureLoaded()
+  }
+}
 
 // State
 const isSaving = ref(false)

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

@@ -238,47 +238,20 @@
           <div class="flex items-center gap-2">
             <Switch
               :model-value="form.proxy_enabled"
-              @update:model-value="(v: boolean) => form.proxy_enabled = v"
+              @update:model-value="handleProxyToggle"
             />
             <span class="text-sm text-muted-foreground">启用代理</span>
           </div>
         </div>
         <div
           v-if="form.proxy_enabled"
-          class="grid grid-cols-2 gap-4 p-3 border rounded-lg bg-muted/50"
+          class="space-y-1.5 p-3 border rounded-lg bg-muted/50"
         >
-          <div class="space-y-1.5">
-            <Label class="text-xs">代理地址 *</Label>
-            <Input
-              v-model="form.proxy_url"
-              placeholder="http://proxy:port 或 socks5://proxy:port"
-            />
-          </div>
-          <div class="grid grid-cols-2 gap-3">
-            <div class="space-y-1.5">
-              <Label class="text-xs">用户名</Label>
-              <Input
-                v-model="form.proxy_username"
-                placeholder="可选"
-                autocomplete="off"
-                data-form-type="other"
-                data-lpignore="true"
-                data-1p-ignore="true"
-              />
-            </div>
-            <div class="space-y-1.5">
-              <Label class="text-xs">密码</Label>
-              <Input
-                v-model="form.proxy_password"
-                type="password"
-                placeholder="可选"
-                autocomplete="new-password"
-                data-form-type="other"
-                data-lpignore="true"
-                data-1p-ignore="true"
-              />
-            </div>
-          </div>
+          <Label class="text-xs">代理节点 *</Label>
+          <ProxyNodeSelect
+            ref="proxyNodeSelectRef"
+            v-model="form.proxy_node_id"
+          />
         </div>
       </div>
     </form>
@@ -322,6 +295,8 @@ import { useFormDialog } from '@/composables/useFormDialog'
 import { createProvider, updateProvider, type ProviderWithEndpointsSummary } from '@/api/endpoints'
 import { parseApiError } from '@/utils/errorParser'
 import { parseNumberInput } from '@/utils/form'
+import ProxyNodeSelect from './ProxyNodeSelect.vue'
+import { useProxyNodesStore } from '@/stores/proxy-nodes'
 
 const props = defineProps<{
   modelValue: boolean
@@ -337,6 +312,16 @@ const emit = defineEmits<{
 
 const { success, error: showError } = useToast()
 const loading = ref(false)
+const proxyNodeSelectRef = ref<InstanceType<typeof ProxyNodeSelect> | null>(null)
+const proxyNodesStore = useProxyNodesStore()
+
+/** 启用代理时懒加载节点列表 */
+function handleProxyToggle(v: boolean) {
+  form.value.proxy_enabled = v
+  if (v) {
+    proxyNodesStore.ensureLoaded()
+  }
+}
 
 // 内部状态
 const internalOpen = computed(() => props.modelValue)
@@ -372,11 +357,9 @@ const form = ref({
   // 超时配置（秒）
   stream_first_byte_timeout: undefined as number | undefined,
   request_timeout: undefined as number | undefined,
-  // 代理配置（扁平化便于表单绑定）
+  // 代理配置
   proxy_enabled: false,
-  proxy_url: '',
-  proxy_username: '',
-  proxy_password: '',
+  proxy_node_id: '',
 })
 
 // 重置表单
@@ -403,9 +386,7 @@ function resetForm() {
     request_timeout: undefined,
     // 代理配置
     proxy_enabled: false,
-    proxy_url: '',
-    proxy_username: '',
-    proxy_password: '',
+    proxy_node_id: '',
   }
 }
 
@@ -438,9 +419,12 @@ function loadProviderData() {
     request_timeout: props.provider.request_timeout ?? undefined,
     // 代理配置
     proxy_enabled: proxy?.enabled ?? false,
-    proxy_url: proxy?.url || '',
-    proxy_username: proxy?.username || '',
-    proxy_password: proxy?.password || '',
+    proxy_node_id: proxy?.node_id || '',
+  }
+
+  // 如果有代理配置，确保加载节点列表（直接调用 store，避免 ref 未挂载时静默失败）
+  if (proxy?.enabled) {
+    proxyNodesStore.ensureLoaded()
   }
 }
 
@@ -462,19 +446,17 @@ const handleSubmit = async () => {
     return
   }
 
-  // 启用代理时必须填写代理地址
-  if (form.value.proxy_enabled && !form.value.proxy_url) {
-    showError('启用代理时必须填写代理地址', '验证失败')
+  // 启用代理时的验证
+  if (form.value.proxy_enabled && !form.value.proxy_node_id) {
+    showError('请选择代理节点', '验证失败')
     return
   }
 
   loading.value = true
   try {
     // 构建代理配置
-    const proxy = form.value.proxy_enabled ? {
-      url: form.value.proxy_url,
-      username: form.value.proxy_username || undefined,
-      password: form.value.proxy_password || undefined,
+    const proxy = form.value.proxy_enabled && form.value.proxy_node_id ? {
+      node_id: form.value.proxy_node_id,
       enabled: true,
     } : null
 

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

@@ -0,0 +1,77 @@
+<template>
+  <div class="space-y-1.5">
+    <Select
+      :model-value="modelValue"
+      :disabled="proxyNodesStore.loading || nodeOptions.length === 0"
+      @update:model-value="(v: string) => $emit('update:modelValue', v)"
+    >
+      <SelectTrigger :class="triggerClass">
+        <SelectValue
+          :placeholder="proxyNodesStore.loading
+            ? '加载节点列表中...'
+            : nodeOptions.length === 0
+              ? '暂无可用节点'
+              : '选择代理节点...'"
+        />
+      </SelectTrigger>
+      <SelectContent>
+        <SelectItem
+          v-for="node in nodeOptions"
+          :key="node.id"
+          :value="node.id"
+        >
+          {{ node.name }}{{ node.region ? ` · ${node.region}` : '' }} ({{ node.ip }}:{{ node.port }})
+        </SelectItem>
+      </SelectContent>
+    </Select>
+    <p
+      v-if="!proxyNodesStore.loading && nodeOptions.length === 0"
+      class="text-xs text-muted-foreground"
+    >
+      暂无在线代理节点，请在「代理节点」页面添加
+    </p>
+  </div>
+</template>
+
+<script setup lang="ts">
+import { computed } from 'vue'
+import {
+  Select,
+  SelectTrigger,
+  SelectValue,
+  SelectContent,
+  SelectItem,
+} from '@/components/ui'
+import { useProxyNodesStore } from '@/stores/proxy-nodes'
+
+const props = defineProps<{
+  modelValue: string
+  triggerClass?: string
+}>()
+
+defineEmits<{
+  'update:modelValue': [value: string]
+}>()
+
+const proxyNodesStore = useProxyNodesStore()
+
+/** 在线节点 + 保留当前已选节点（可能已离线） */
+const nodeOptions = computed(() => {
+  const online = proxyNodesStore.onlineNodes
+  if (props.modelValue) {
+    const found = online.find(n => n.id === props.modelValue)
+    if (!found) {
+      const allNode = proxyNodesStore.nodes.find(n => n.id === props.modelValue)
+      if (allNode) return [allNode, ...online]
+    }
+  }
+  return online
+})
+
+/** 供父组件调用：启用代理时懒加载节点列表 */
+function ensureLoaded() {
+  proxyNodesStore.ensureLoaded()
+}
+
+defineExpose({ ensureLoaded })
+</script>