fix texthooker gate, overlay fallback, and control server byte limit

- gate --texthooker flag on both CLI useTexthooker arg and plugin texthookerEnabled
- remove erroneous return that blocked legacy app startup fallback after control command failure
- fix open-config-settings to only skipRender when window actually opened
- track raw byte count for accurate 64KB limit in app control server

launcher/mpv.ts

@@ -1058,7 +1058,6 @@ export async function startOverlay(
       clearOverlayManagedByLauncher();
       state.overlayProc = null;
     }
-    return;
   }
 
   const appAlreadyRunning = isAppAlreadyRunning(appPath, args.logLevel);