渠道: 移除供应商下拉, 格式多选为唯一配置

- 前端渠道表单去掉"供应商"下拉, 只保留"支持的 API 格式"多选(默认 chat)
- 后端 provider 改为可选字段: 为空时按 formats 推断(仅 messages→anthropic,
  含 responses→openai, 否则 compatible), 兼容旧数据
- 保存时校验至少选择一种格式

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

web/src/views/admin/ChannelsView.vue

@@ -18,8 +18,7 @@ const busyId = ref<number | null>(null)
 
 const form = reactive({
   name: '',
-  provider: 'openai' as 'openai' | 'anthropic' | 'compatible',
-  formats: [] as string[],
+  formats: ['chat'] as string[],
   base_url: '',
   api_key: '',
   weight: 1,
@@ -29,17 +28,6 @@ const form = reactive({
   enabled: true,
 })
 
-// 按供应商推断默认支持的协议格式
-function defaultFormats(p: string): string[] {
-  if (p === 'anthropic') return ['messages']
-  if (p === 'openai') return ['chat', 'responses']
-  return ['chat']
-}
-
-function onProviderChange() {
-  form.formats = defaultFormats(form.provider)
-}
-
 async function load() {
   try {
     const { data } = await http.get('/admin/channels')
@@ -52,7 +40,7 @@ async function load() {
 function openCreate() {
   editing.value = null
   Object.assign(form, {
-    name: '', provider: 'openai', formats: defaultFormats('openai'), base_url: '', api_key: '',
+    name: '', formats: ['chat'], base_url: '', api_key: '',
     weight: 1, priority: 0, timeout_ms: 120000, max_concurrency: 16, enabled: true,
   })
   editOpen.value = true
@@ -61,7 +49,7 @@ function openCreate() {
 function openEdit(ch: Channel) {
   editing.value = ch
   Object.assign(form, {
-    name: ch.name, provider: ch.provider, formats: [...(ch.formats || defaultFormats(ch.provider))],
+    name: ch.name, formats: [...(ch.formats?.length ? ch.formats : ['chat'])],
     base_url: ch.base_url, api_key: '',
     weight: ch.weight, priority: ch.priority, timeout_ms: ch.timeout_ms,
     max_concurrency: ch.max_concurrency, enabled: ch.enabled,
@@ -70,6 +58,10 @@ function openEdit(ch: Channel) {
 }
 
 async function save() {
+  if (form.formats.length === 0) {
+    toast.err('请至少选择一种 API 格式')
+    return
+  }
   saving.value = true
   const payload = {
     ...form,
@@ -199,21 +191,7 @@ onMounted(load)
 
     <Modal :open="editOpen" :title="editing ? '编辑渠道' : '添加渠道'" @close="editOpen = false">
       <div class="space-y-4">
-        <div class="grid grid-cols-2 gap-4">
-          <Input v-model="form.name" label="名称" placeholder="openai" />
-          <label class="block">
-            <span class="mb-1.5 block text-xs font-medium text-muted">供应商</span>
-            <select
-              v-model="form.provider"
-              class="h-10 w-full rounded-md border border-edge2 bg-surface px-3 text-sm text-ink outline-none focus:border-accent"
-              @change="onProviderChange"
-            >
-              <option value="openai">OpenAI</option>
-              <option value="anthropic">Anthropic</option>
-              <option value="compatible">兼容</option>
-            </select>
-          </label>
-        </div>
+        <Input v-model="form.name" label="名称" placeholder="openai" />
         <div>
           <span class="mb-1.5 block text-xs font-medium text-muted">支持的 API 格式</span>
           <div class="flex flex-wrap gap-2">