fix(core): should use AttachmentViewerView in split view and standalone page (#12323)

Closes: [AF-2564](https://linear.app/affine-design/issue/AF-2564/pdf-split-view-多了-header)

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

- **Refactor**
  - Improved code clarity and maintainability with clearer comments and streamlined property usage.
  - Updated the workspace attachment page to use a more context-appropriate attachment viewer component.
- **Style**
  - Minor formatting improvements for better code readability.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/frontend/core/src/blocksuite/attachment-viewer/index.tsx

@@ -7,7 +7,7 @@ import { buildAttachmentProps } from './utils';
 import { Titlebar } from './viewer';
 import * as styles from './viewer.css';
 
-// In Peek view
+// Peek view
 export const AttachmentViewer = ({ model }: AttachmentViewerProps) => {
   const props = buildAttachmentProps(model);
 
@@ -19,7 +19,7 @@ export const AttachmentViewer = ({ model }: AttachmentViewerProps) => {
   );
 };
 
-// In View container
+// Split view or standalone page
 export const AttachmentViewerView = ({ model }: AttachmentViewerProps) => {
   const props = buildAttachmentProps(model);
 

packages/frontend/core/src/blocksuite/attachment-viewer/pdf/pdf-viewer.tsx

@@ -39,6 +39,7 @@ function calculatePageNum(el: HTMLElement, pageCount: number) {
   const cursor = Math.min(index, pageCount - 1);
   return cursor;
 }
+
 export interface PDFViewerInnerProps {
   pdf: PDF;
   state: Extract<PDFRendererState, { status: PDFStatus.Opened }>;