feat: 三协议互转网关 + 鉴权修复 + 管理端增强

后端
- 新增 proxy/convert 三协议（chat/messages/responses）请求、响应与 SSE 流式互转，
  以 Chat 为中间模型；usage.go 统一提取三协议 token 用量（含单测）
- gateway: 跨协议调度（渠道未声明客户端协议时转为渠道首选格式），
  streamResponse 按 \n\n 分块逐行转换直通，bufferResponse 转换失败时剥非 JSON 前缀
- gateway: 新增 SetUsageRecorder 注入异步用量记录器
- auth_llm: 修复 key_prefix 查询长度错配（[:8] vs 存储的 [:12]）导致全部 401；
  修复长度 8-11 的 key 切片越界 panic；统一 unauthorized 响应
- usage: 日报表改为增量累加 upsert，避免多次 flush 互相清零；记录协议/错误码/时延等字段
- channel: 新增渠道并发槽 TryAcquire；健康检查支持可配置参数
- api: 新增 admin 渠道/模型/系统配置管理端点（旧端点保留兼容）

前端
- 新增渠道管理、模型管理、系统配置视图与 ChannelModelsDrawer
- 新增 ui 基础组件（Button/Badge/Input/Modal）与 protocol.ts
- 调整 Toast 样式、密钥页、路由菜单；dev 代理默认指向 3000 端口

frontend/src/views/dashboard/KeyView.vue

@@ -87,6 +87,10 @@
 
           <div class="flex items-center justify-end gap-3 border-t border-base-300/40 pt-4">
             <button type="button" @click="goBack" class="btn btn-ghost btn-sm">Back</button>
+            <button type="button" @click="testChannel" class="btn btn-warning btn-sm" :disabled="testing">
+              <span v-if="testing" class="loading loading-spinner loading-xs" aria-hidden="true"></span>
+              Test Connection
+            </button>
             <button type="submit" class="btn btn-primary btn-sm px-5" :disabled="updating">
               <span v-if="updating" class="loading loading-spinner loading-xs" aria-hidden="true"></span>
               Save Changes
@@ -94,6 +98,47 @@
           </div>
         </form>
       </div>
+
+      <!-- Model Bindings -->
+      <div class="card border border-base-300/60 bg-base-100 shadow-sm">
+        <div class="card-body gap-4 p-4 sm:p-6">
+          <div class="flex items-center justify-between">
+            <h2 class="text-xs font-semibold uppercase tracking-wider text-base-content/50">Model Bindings</h2>
+            <button class="btn btn-primary btn-sm" @click="openAddModelModal">
+              <PlusIcon class="h-4 w-4" aria-hidden="true" />Add Model
+            </button>
+          </div>
+          
+          <div v-if="bindings.length > 0" class="overflow-x-auto">
+            <table class="table table-sm">
+              <thead>
+                <tr class="text-xs uppercase tracking-wider text-base-content/50">
+                  <th>Model Name</th>
+                  <th>Upstream Model</th>
+                  <th class="text-right">Weight</th>
+                  <th class="text-right"><span class="sr-only">Actions</span></th>
+                </tr>
+              </thead>
+              <tbody>
+                <tr v-for="b in bindings" :key="b.id" class="border-base-300/40">
+                  <td class="font-medium">{{ b.model_name }}</td>
+                  <td class="font-mono text-xs">{{ b.upstream_model }}</td>
+                  <td class="text-right">{{ b.weight }}</td>
+                  <td class="text-right">
+                    <button class="btn btn-ghost btn-xs btn-square text-error" @click="confirmDeleteBinding(b)"
+                      aria-label="Delete binding">
+                      <TrashIcon class="h-4 w-4" aria-hidden="true" />
+                    </button>
+                  </td>
+                </tr>
+              </tbody>
+            </table>
+          </div>
+          <div v-else class="py-6 text-center text-sm text-base-content/50">
+            No model bindings configured.
+          </div>
+        </div>
+      </div>
     </div>
 
     <!-- Loading state -->
@@ -104,22 +149,59 @@
         </div>
       </div>
     </div>
+
+    <!-- Add Model Modal -->
+    <dialog ref="addModelModalRef" class="modal">
+      <div class="modal-box max-w-lg px-0 sm:px-6">
+        <form method="dialog">
+          <button class="btn btn-circle btn-ghost btn-sm absolute right-2 top-2" aria-label="Close dialog">✕</button>
+        </form>
+        <h3 class="mb-4 text-lg font-bold">Add Model Binding</h3>
+        <form @submit.prevent="addModelBinding" class="space-y-4">
+          <label class="floating-label">
+            <span>Model ID *</span>
+            <input v-model.number="newBinding.model_id" type="number" placeholder="Model ID" class="input w-full" required />
+          </label>
+          <label class="floating-label">
+            <span>Upstream Model Name *</span>
+            <input v-model="newBinding.upstream_model" type="text" placeholder="e.g. gpt-4o" class="input w-full" required />
+          </label>
+          <label class="floating-label">
+            <span>Weight</span>
+            <input v-model.number="newBinding.weight" type="number" min="1" placeholder="1" class="input w-full" />
+          </label>
+          <div class="modal-action">
+            <button type="button" class="btn btn-ghost" @click="closeAddModelModal">Cancel</button>
+            <button type="submit" class="btn btn-primary" :disabled="addingModel">
+              {{ addingModel ? 'Adding...' : 'Add' }}
+            </button>
+          </div>
+        </form>
+      </div>
+      <form method="dialog" class="modal-backdrop">
+        <button aria-label="Close dialog">close</button>
+      </form>
+    </dialog>
   </div>
 </template>
 
 <script setup lang="ts">
 import { computed, onMounted, ref } from 'vue';
 import { useRoute, useRouter } from 'vue-router';
-import { useChannelStore, type Channel } from '../../stores/channel';
+import { useChannelStore, type Channel, type ChannelModelBinding } from '../../stores/channel';
 import BreadcrumbHeader from '@/components/dashboard/BreadcrumbHeader.vue';
 import { useToast } from '@/composables/toast';
 
+import { PlusIcon, TrashIcon } from '@lucide/vue';
+
 const route = useRoute();
 const router = useRouter();
 const channelStore = useChannelStore();
 const { setToast } = useToast();
 const updating = ref(false);
+const testing = ref(false);
 const api_key = ref('');
+const bindings = ref<ChannelModelBinding[]>([]);
 
 const channelId = computed(() => route.query.id);
 const ch = computed(() => channelStore.channel);
@@ -127,9 +209,16 @@ const ch = computed(() => channelStore.channel);
 onMounted(async () => {
   if (channelId.value) {
     await channelStore.fetchChannel(channelId.value as string);
+    await fetchBindings();
   }
 });
 
+const fetchBindings = async () => {
+  if (channelId.value) {
+    bindings.value = await channelStore.fetchChannelModels(channelId.value as string);
+  }
+};
+
 const toggleEnabled = () => {
   if (!ch.value) return;
   ch.value.enabled = !ch.value.enabled;
@@ -163,7 +252,65 @@ const updateCh = async () => {
   }
 };
 
+const testChannel = async () => {
+  if (!ch.value) return;
+  testing.value = true;
+  try {
+    const result = await channelStore.testChannel(ch.value.id);
+    setToast(`Connection OK (${result.data?.latency_ms}ms)`, 'success');
+  } catch (err: any) {
+    setToast(err.response?.data?.error || 'Connection test failed', 'error');
+  } finally {
+    testing.value = false;
+  }
+};
+
 const goBack = () => {
   router.push({ name: 'Channels' });
 };
+
+// Model binding
+const addModelModalRef = ref<HTMLDialogElement | null>(null);
+const addingModel = ref(false);
+const newBinding = ref({
+  model_id: 0,
+  upstream_model: '',
+  weight: 1,
+});
+
+const openAddModelModal = () => {
+  newBinding.value = { model_id: 0, upstream_model: '', weight: 1 };
+  addModelModalRef.value?.showModal();
+};
+
+const closeAddModelModal = () => {
+  addModelModalRef.value?.close();
+};
+
+const addModelBinding = async () => {
+  if (!channelId.value || !newBinding.value.model_id || !newBinding.value.upstream_model) return;
+  addingModel.value = true;
+  try {
+    await channelStore.addChannelModel(channelId.value as string, newBinding.value);
+    setToast('Model binding added', 'success');
+    closeAddModelModal();
+    await fetchBindings();
+  } catch (err: any) {
+    setToast(err.response?.data?.error || 'Failed to add binding', 'error');
+  } finally {
+    addingModel.value = false;
+  }
+};
+
+const confirmDeleteBinding = async (b: ChannelModelBinding) => {
+  if (confirm(`Remove binding for model "${b.model_name}"?`)) {
+    try {
+      await channelStore.deleteChannelModel(channelId.value as string, b.id);
+      setToast('Binding removed', 'success');
+      await fetchBindings();
+    } catch (err: any) {
+      setToast('Delete failed', 'error');
+    }
+  }
+};
 </script>