Surface OEM AUTO_START blocks in UnifiedPush settings status.

TCL App Boot can drop NEW_ENDPOINT; show a clear allow-auto-start hint when detected.

src/app/utils/backgroundSync.ts

@@ -16,6 +16,8 @@ type UnifiedPushStatus = {
   distributor: string;
   distributors: string[] | string;
   lastFailure?: string;
+  /** OEM App Boot / AUTO_START is blocking distributor broadcasts (e.g. TCL). */
+  autoStartBlocked?: boolean;
 };
 
 type UnifiedPushEndpointEvent = {