feat: 云账号编辑功能 + 通知渠道种子数据 + 修复mock.go编译错误

- 新增 PUT /cloud-accounts/:id 后端端点（UpdateCloudAccount handler + 路由注册）
- 前端 CloudAccountManager 添加编辑弹窗：复用创建表单，凭证留空保持不变
- 修复 scripts/mock.go 编译错误：补充缺失的 generateNotifyChannels 函数（5种通知渠道种子）
- 包含前序未提交的告警通知渠道 CRUD 后端API + AlertManager 通知配置前端UI

frontend/src/components/cloud/CloudAccountManager.tsx

@@ -16,6 +16,7 @@ import {
   Plus,
   Search,
   Trash2,
+  Pencil,
   Key,
   Cloud,
   CheckCircle2,
@@ -47,9 +48,10 @@ export function CloudAccountManager() {
   const [searchQuery, setSearchQuery] = useState('');
   const [selectedProvider, setSelectedProvider] = useState<string>('all');
 
-  // 创建账号表单状态
+  // 创建/编辑账号表单状态
   const [formOpen, setFormOpen] = useState(false);
   const [submitting, setSubmitting] = useState(false);
+  const [editingAccount, setEditingAccount] = useState<any>(null);
   const [formData, setFormData] = useState({
     name: '',
     provider: 'aliyun',
@@ -60,6 +62,7 @@ export function CloudAccountManager() {
   });
 
   const resetForm = () => {
+    setEditingAccount(null);
     setFormData({
       name: '',
       provider: 'aliyun',
@@ -75,22 +78,40 @@ export function CloudAccountManager() {
     setFormOpen(true);
   };
 
-  const handleCreate = async () => {
+  const handleOpenEdit = (account: any) => {
+    setEditingAccount(account);
+    setFormData({
+      name: account.name || '',
+      provider: account.provider || 'aliyun',
+      access_key: '',
+      secret_key: '',
+      monthly_cost: String(account.monthly_cost ?? 0),
+      status: account.status || 'active',
+    });
+    setFormOpen(true);
+  };
+
+  const handleSubmit = async () => {
     if (!formData.name.trim() || !formData.provider.trim()) return;
     try {
       setSubmitting(true);
-      await cloudApi.createAccount({
+      const payload: any = {
         name: formData.name.trim(),
         provider: formData.provider,
         access_key: formData.access_key.trim(),
         secret_key: formData.secret_key.trim(),
         monthly_cost: Number(formData.monthly_cost) || 0,
         status: formData.status,
-      });
+      };
+      if (editingAccount) {
+        await cloudApi.updateAccount(editingAccount.id, payload);
+      } else {
+        await cloudApi.createAccount(payload);
+      }
       setFormOpen(false);
       loadData();
     } catch (e) {
-      console.error('创建云账号失败:', e);
+      console.error(editingAccount ? '更新云账号失败:' : '创建云账号失败:', e);
     } finally {
       setSubmitting(false);
     }
@@ -297,6 +318,14 @@ export function CloudAccountManager() {
                       </div>
                     </div>
                     <div className="flex items-center gap-1">
+                      <Button
+                        variant="ghost"
+                        size="icon"
+                        className="h-8 w-8 text-slate-400 hover:text-blue-400"
+                        onClick={() => handleOpenEdit(account)}
+                      >
+                        <Pencil className="h-4 w-4" />
+                      </Button>
                       <Button
                         variant="ghost"
                         size="icon"
@@ -336,10 +365,10 @@ export function CloudAccountManager() {
           <DialogHeader>
             <DialogTitle className="text-slate-100 flex items-center gap-2">
               <Cloud className="h-5 w-5 text-blue-400" />
-              添加云账号
+              {editingAccount ? '编辑云账号' : '添加云账号'}
             </DialogTitle>
             <DialogDescription className="text-slate-400">
-              录入多云平台的访问凭证，用于资源同步与成本统计
+              {editingAccount ? '修改账号信息和访问凭证，留空则保持原凭证不变' : '录入多云平台的访问凭证，用于资源同步与成本统计'}
             </DialogDescription>
           </DialogHeader>
 
@@ -375,7 +404,10 @@ export function CloudAccountManager() {
             </div>
 
             <div className="space-y-1.5">
-              <Label className="text-slate-300">AccessKey</Label>
+              <Label className="text-slate-300">
+                AccessKey
+                {editingAccount && <span className="text-xs text-slate-500 ml-2">留空保持不变</span>}
+              </Label>
               <Input
                 placeholder="LTAI..."
                 value={formData.access_key}
@@ -385,7 +417,10 @@ export function CloudAccountManager() {
             </div>
 
             <div className="space-y-1.5">
-              <Label className="text-slate-300">SecretKey</Label>
+              <Label className="text-slate-300">
+                SecretKey
+                {editingAccount && <span className="text-xs text-slate-500 ml-2">留空保持不变</span>}
+              </Label>
               <Input
                 type="password"
                 placeholder="••••••••"
@@ -429,10 +464,10 @@ export function CloudAccountManager() {
             <Button
               className="bg-blue-600 hover:bg-blue-700"
               disabled={!formData.name.trim() || submitting}
-              onClick={handleCreate}
+              onClick={handleSubmit}
             >
-              {submitting ? <Loader2 className="h-4 w-4 mr-2 animate-spin" /> : <Plus className="h-4 w-4 mr-2" />}
-              创建账号
+              {submitting ? <Loader2 className="h-4 w-4 mr-2 animate-spin" /> : editingAccount ? <Pencil className="h-4 w-4 mr-2" /> : <Plus className="h-4 w-4 mr-2" />}
+              {editingAccount ? '保存修改' : '创建账号'}
             </Button>
           </DialogFooter>
         </DialogContent>