fix critical messaging bug: onMessage was discarding return values

The onMessage wrapper in messaging.ts was only sending {success: true}
instead of the actual handler return value. This caused the popup to
receive undefined state even though the background worker was correctly
storing it.

Changes:
- messaging.ts: Changed onMessage to forward handler return values
- background service-worker.ts: Added comprehensive logging
- popup.ts: Added state change listener and detailed logging

This fixes the issue where popup showed 'Go to...' even when on the
following page.

packages/extension/src/background/service-worker.ts

···
  * Update state from content script
  */
 async function handleStateUpdate(newState: Partial<ExtensionState>): Promise<void> {
+  console.log('[Background] 📥 Received state update:', newState);
   const currentState = await getState();
+  console.log('[Background] 📋 Current state before update:', currentState);
   const updatedState = { ...currentState, ...newState };
   await setState(updatedState);
-  console.log('[Background] State updated:', updatedState);
+  console.log('[Background] ✅ State updated successfully:', updatedState);
+
+  // Verify the state was saved
+  const verifyState = await getState();
+  console.log('[Background] 🔍 Verified state from storage:', verifyState);
 }
 
 /**

packages/extension/src/lib/messaging.ts

···
  * Listen for messages
  */
 export function onMessage(
-  handler: (message: Message, sender: chrome.runtime.MessageSender) => void | Promise<void>
+  handler: (message: Message, sender: chrome.runtime.MessageSender) => any | Promise<any>
 ): void {
   chrome.runtime.onMessage.addListener((message, sender, sendResponse) => {
     const result = handler(message, sender);
 
     // Handle async handlers
     if (result instanceof Promise) {
-      result.then(() => sendResponse({ success: true }))
+      result.then((data) => sendResponse(data))
         .catch(error => sendResponse({ success: false, error: error.message }));
       return true; // Keep message channel open for async response
     }
 
-    sendResponse({ success: true });
+    // Send sync result
+    sendResponse(result);
   });
 }

packages/extension/src/popup/popup.ts

···
  * Update UI based on extension state
  */
 function updateUI(state: ExtensionState): void {
-  console.log('[Popup] Updating UI:', state);
+  console.log('[Popup] 🎨 Updating UI with state:', state);
+  console.log('[Popup] 🎯 Current status:', state.status);
+  console.log('[Popup] 🌐 Platform:', state.platform);
+  console.log('[Popup] 📄 Page type:', state.pageType);
 
   switch (state.status) {
     case 'idle':
···
  * Initialize popup
  */
 async function init(): Promise<void> {
-  console.log('[Popup] Initializing...');
+  console.log('[Popup] 🚀 Initializing popup...');
 
   // Get current state
+  console.log('[Popup] 📡 Requesting state from background...');
   const state = await sendToBackground<ExtensionState>({
     type: MessageType.GET_STATE
   });
 
+  console.log('[Popup] 📥 Received state from background:', state);
   updateUI(state);
 
   // Set up event listeners
···
     updateUI(state);
   });
 
+  // Listen for storage changes (when background updates state)
+  chrome.storage.onChanged.addListener((changes, areaName) => {
+    if (areaName === 'local' && changes.extensionState) {
+      const newState = changes.extensionState.newValue;
+      console.log('[Popup] 🔄 Storage changed, new state:', newState);
+      updateUI(newState);
+    }
+  });
+
   // Poll for updates if currently scraping
   if (state.status === 'scraping') {
     pollForUpdates();
   }
 
-  console.log('[Popup] Ready');
+  console.log('[Popup] ✅ Popup ready');
 }
 
 // Initialize when DOM is ready