feat: add support for release channels in version upgrade and node agent updates

- Introduced ReleaseChannel type to manage stable and preview releases.
- Updated DashboardTopbar to handle version upgrades based on selected release channel.
- Enhanced node detail page to allow manual checks for agent updates on stable and preview channels.
- Modified API endpoints to support fetching and upgrading based on release channels.
- Updated UI components to reflect changes in version checking and upgrade processes.
- Added tests for new functionality related to preview releases and agent updates.

atsf_server/web/features/nodes/utils.ts

@@ -54,6 +54,10 @@ export function getApplyLabel(result: NodeItem['latest_apply_result']) {
 
 export function getUpdateMode(node: NodeItem) {
   if (node.update_requested) {
+    if (node.update_channel === 'preview') {
+      return { label: '等待预览更新', variant: 'warning' as const };
+    }
+
     return { label: '等待更新', variant: 'warning' as const };
   }