fix: comprehensive extension context invalidated handling

entrypoints/popup/Popup.tsx

@@ -1,13 +1,24 @@
 import React, { useEffect, useState } from 'react';
 import { createRoot } from 'react-dom/client';
 
+// ─── Safe chrome storage wrapper ─────────────────────────────────────────────
+
+function safeStorageGet(keys: string[], callback: (result: Record<string, string>) => void) {
+  try {
+    if (typeof chrome === 'undefined' || !chrome.runtime?.id) return;
+    chrome.storage.local.get(keys, callback);
+  } catch (err) {
+    console.warn('LexAI: Extension context invalidated', err);
+  }
+}
+
 function Popup() {
   const [configured, setConfigured] = useState(false);
   const [provider, setProvider] = useState('');
   const [model, setModel] = useState('');
 
   useEffect(() => {
-    chrome.storage.local.get(["provider", "apiKey", "model"], (result: Record<string, string>) => {
+    safeStorageGet(["provider", "apiKey", "model"], (result) => {
       if (result.apiKey) {
         setConfigured(true);
         setProvider(result.provider || 'openai');
@@ -16,7 +27,15 @@ function Popup() {
     });
   }, []);
 
-  const openSettings = () => chrome.runtime.openOptionsPage();
+  const openSettings = () => {
+    try {
+      if (typeof chrome !== 'undefined' && chrome.runtime?.id) {
+        chrome.runtime.openOptionsPage();
+      }
+    } catch (err) {
+      console.warn('LexAI: Extension context invalidated', err);
+    }
+  };
 
   return (
     <div style={{ padding: 16, fontFamily: 'system-ui, sans-serif', color: '#1e1e2e' }}>