fix(core): ai user message word break failed (#12347)

![截屏2025-05-19 10.11.58.png](https://graphite-user-uploaded-assets-prod.s3.amazonaws.com/MyktQ6Qwc7H6TiRCFoYN/549544df-c1f1-49da-8884-f666e46a0419.png)

<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit

- **Style**
  - Updated chat content containers to use the full available width, improving display on different screen sizes.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/frontend/core/src/blocksuite/ai/chat-panel/content/pure-text.ts

@@ -8,7 +8,7 @@ export class ChatContentPureText extends ShadowlessElement {
     .chat-content-pure-text {
       display: inline-block;
       text-align: left;
-      max-width: 800px;
+      max-width: 100%;
       max-height: 500px;
       overflow-y: auto;
       overflow-x: hidden;

packages/frontend/core/src/blocksuite/ai/chat-panel/message/user.ts

@@ -47,7 +47,11 @@ export class ChatMessageUser extends WithDisposable(ShadowlessElement) {
             .images=${item.attachments}
           ></chat-content-images>`
         : nothing}
-      <div class="text-content-wrapper" data-test-id="chat-content-user-text">
+      <div
+        class="text-content-wrapper"
+        data-test-id="chat-content-user-text"
+        style="max-width: 100%;"
+      >
         <chat-content-pure-text .text=${item.content}></chat-content-pure-text>
       </div>
     `;