fix: start system default sync channels by default

Create and restart paths enable IsSystemDefault channels; SyncPage auto-starts after save.

Co-authored-by: Cursor <cursoragent@cursor.com>

web/src/SyncPage.tsx

@@ -348,10 +348,21 @@ export function SyncPage(props: {
     setBusy(true);
     try {
       const body = toChannelBody(v, editing?.id);
-      if (editing) await updateSyncChannel(session, editing.id, body);
-      else await createSyncChannel(session, body);
+      const saved = editing
+        ? await updateSyncChannel(session, editing.id, body)
+        : await createSyncChannel(session, body);
+      const id = (saved as SyncChannel)?.id || editing?.id;
+      if (id) {
+        try {
+          await startSyncChannel(session, id);
+          setInfo("同步通道已保存并启动");
+        } catch {
+          setInfo("同步通道已保存（启动失败时可手动点「启动」）");
+        }
+      } else {
+        setInfo("同步通道已保存");
+      }
       setOpen(false);
-      setInfo("同步通道已保存");
       await refresh();
     } catch (e: any) {
       message.error(e.message || String(e));