chrome.runtime.onMessage.addListener((e,o,t)=>{if(!e||typeof e!="object"||!("type"in e))return;const r=n=>t(n);return e.type==="PING"?(r({ok:!0,type:"PONG"}),!0):(r({ok:!1,error:"Unsupported message in background (MVP)."}),!0)});
