fix(core): hide footer actions for independent ai chat (#13177)

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

## Summary by CodeRabbit

* **New Features**
* Added support for an "independent mode" in assistant chat messages,
which hides editor actions when enabled.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

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

@@ -79,6 +79,9 @@ export class ChatMessageAssistant extends WithDisposable(ShadowlessElement) {
   @property({ attribute: false })
   accessor notificationService!: NotificationService;
 
+  @property({ attribute: false })
+  accessor independentMode!: boolean;
+
   get state() {
     const { isLast, status } = this;
     return isLast
@@ -175,7 +178,7 @@ export class ChatMessageAssistant extends WithDisposable(ShadowlessElement) {
         : EdgelessEditorActions
       : null;
 
-    const showActions = host && !!markdown;
+    const showActions = host && !!markdown && !this.independentMode;
 
     return html`
       <chat-copy-more

packages/frontend/core/src/blocksuite/ai/components/ai-chat-messages/ai-chat-messages.ts

@@ -327,6 +327,7 @@ export class AIChatMessages extends WithDisposable(ShadowlessElement) {
                     .notificationService=${this.notificationService}
                     .retry=${() => this.retry()}
                     .width=${this.width}
+                    .independentMode=${this.independentMode}
                   ></chat-message-assistant>`;
                 } else if (isChatAction(item) && this.host) {
                   return html`<chat-message-action