fix(editor): improve pdf embed viewer UX (#11641)

Closes: [BS-3101](https://linear.app/affine-design/issue/BS-3101/pdf-embed-模式的选中框选-和点开看详情有比较大的问题)

### What's Changed!

* Fixed disable pointer event in native pdf viewer by dragging
* Disable opening peek view with pdf viewer in readonly and sharing modes

blocksuite/affine/blocks/attachment/src/attachment-block.ts

@@ -28,7 +28,7 @@ import { checkAttachmentBlob, downloadAttachmentBlob } from './utils';
 
 @Peekable({
   enableOn: ({ model }: AttachmentBlockComponent) => {
-    return model.props.type.endsWith('pdf');
+    return !model.doc.readonly && model.props.type.endsWith('pdf');
   },
 })
 export class AttachmentBlockComponent extends CaptionedBlockComponent<AttachmentBlockModel> {

blocksuite/affine/blocks/attachment/src/embed.ts

@@ -146,17 +146,20 @@ const embedConfig: AttachmentEmbedConfig[] = [
       // More options: https://tinytip.co/tips/html-pdf-params/
       // https://chromium.googlesource.com/chromium/src/+/refs/tags/121.0.6153.1/chrome/browser/resources/pdf/open_pdf_params_parser.ts
       const parameters = '#toolbar=0';
-      return html`<iframe
-        style="width: 100%; color-scheme: auto;"
-        height="480"
-        src=${blobUrl + parameters}
-        loading="lazy"
-        scrolling="no"
-        frameborder="no"
-        allowTransparency
-        allowfullscreen
-        type="application/pdf"
-      ></iframe>`;
+      return html`
+        <iframe
+          style="width: 100%; color-scheme: auto;"
+          height="480"
+          src=${blobUrl + parameters}
+          loading="lazy"
+          scrolling="no"
+          frameborder="no"
+          allowTransparency
+          allowfullscreen
+          type="application/pdf"
+        ></iframe>
+        <div class="affine-attachment-embed-event-mask"></div>
+      `;
     },
   },
   {

blocksuite/affine/blocks/attachment/src/styles.ts

@@ -136,4 +136,9 @@ export const styles = css`
     width: 100%;
     height: 100%;
   }
+
+  .affine-attachment-embed-event-mask {
+    position: absolute;
+    inset: 0;
+  }
 `;