fix(ui): preserve config save error after loadChannels refresh

- Store save error before calling loadChannels
- Apply error after refresh completes
- Prevents loadChannels from clearing the error prematurely
- Fixes Codex P1: save error now persists for user to see

ui/src/ui/app-channels.ts

@@ -27,11 +27,12 @@ export async function handleWhatsAppLogout(host: OpenClawApp) {
 export async function handleChannelConfigSave(host: OpenClawApp) {
   host.channelsError = null;
   await saveConfig(host);
-  if (host.lastError) {
-    host.channelsError = host.lastError;
-  }
+  const saveError = host.lastError;
   await loadConfig(host);
   await loadChannels(host, true);
+  if (saveError) {
+    host.channelsError = saveError;
+  }
 }
 
 export async function handleChannelConfigReload(host: OpenClawApp) {