Update version to 1.10.9 in manifest.json and refactor AI message han…

…dling in message-handler.js

- Bumped version number in manifest.json to 1.10.9.
- Refactored updateAIMessage function in message-handler.js to select the last updating AI message more efficiently, improving message handling during updates.

manifest.json

@@ -1,7 +1,7 @@
 {
   "manifest_version": 3,
   "name": "Cerebr",
-  "version": "1.10.8",
+  "version": "1.10.9",
   "description": "Cerebr - 智能AI聊天助手",
   "content_security_policy": {
     "extension_pages": "script-src 'self' 'wasm-unsafe-eval'; object-src 'self'"

src/handlers/message-handler.js

@@ -135,8 +135,7 @@ export async function updateAIMessage({
     config,
     messageHandlerConfig
 }) {
-    const messages = chatContainer.getElementsByClassName('ai-message');
-    const lastMessage = messages.length ? messages[messages.length - 1] : null;
+    const lastMessage = chatContainer.querySelector('.ai-message.updating');
     let rawText = text;
 
     if (lastMessage) {