fix(editor): limit at members list length (#12529)

Closes: BS-3009

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

- **New Features**
  - The mention members menu now displays up to three members, with a localized hint indicating the number of additional hidden members.
- **Localization**
  - Added a new translation key for the overflow members hint in the English language pack.
- **Chores**
  - Updated translation completeness statistics for the "es-CL" locale.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/frontend/core/src/modules/at-menu-config/services/index.ts

@@ -594,6 +594,14 @@ export class AtMenuConfigService extends Service {
       items,
       loading: this.memberSearchService.isLoading$.signal,
       hidden,
+      maxDisplay: 3,
+      overflowText: computed(() => {
+        const totalCount = this.memberSearchService.result$.signal.value.length;
+        const remainingCount = totalCount - 3;
+        return I18n.t('com.affine.editor.at-menu.more-members-hint', {
+          count: remainingCount,
+        });
+      }),
     };
   }