fix: v1.0.5 stability hotfixes (ACK security and event jitter)

extension/content.js

@@ -206,8 +206,6 @@
             return; // Ignore event caused by our programmatic action
         }
         
-        setTargetState(null); // Reset on mismatch or unhandled event
-
         chrome.runtime.sendMessage({
             type: 'CONTENT_EVENT',
             action,

server/index.js

@@ -341,7 +341,7 @@ io.on('connection', (socket) => {
             // Security: Only relay ACK if both peers are in the same room
             if (senderMapping && targetMapping && senderMapping.roomId === targetMapping.roomId) {
                 io.to(targetSocketId).emit(EVENTS.EVENT_ACK, { 
-                    senderId: data.senderId,
+                    senderId: senderMapping.peerId,
                     actionTimestamp: data.actionTimestamp
                 });
             } else {