fix(core): some ux enhancements on comments (#13105)

fix PD-2688

#### PR Dependency Tree


* **PR #13105** 👈

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

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

## Summary by CodeRabbit

* **New Features**
* Added configurable support for enabling or disabling inline comments.
* Introduced visual indication (strikethrough) for deleted comments in
the comment sidebar.
  * Sidebar now shows when a comment is no longer present in the editor.
* Added a localized placeholder prompt ("What are your thoughts?") in
the comment editor.
* Integrated detailed event tracking for comment actions: create, edit,
delete, and resolve.

* **Improvements**
  * Inline comments are now disabled in shared mode.
* Enhanced synchronization between editor comments and provider state to
remove stale comments.
  * Inline comment features now respect the document’s read-only state.
* Improved mention handling and tracking in comment creation and
editing.
* Comment manager and entities now dynamically track comments present in
the editor.
* Comment configuration updated to enable or disable inline comments
based on settings.

* **Bug Fixes**
  * Prevented comment block creation when in read-only mode.

* **Localization**
  * Added English localization for the comment prompt.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->


#### PR Dependency Tree


* **PR #13105** 👈

This tree was auto-generated by
[Charcoal](https://github.com/danerwilliams/charcoal)

blocksuite/affine/blocks/root/src/page/page-root-block.ts

@@ -305,7 +305,10 @@ export class PageRootBlockComponent extends BlockComponent<RootBlockModel> {
       );
 
       // make sure there is a block can be focused
-      if (notes.length === 0 || notes[notes.length - 1].children.length === 0) {
+      if (
+        !this.store.readonly$.value &&
+        (notes.length === 0 || notes[notes.length - 1].children.length === 0)
+      ) {
         this.std.command.exec(appendParagraphCommand);
         return;
       }
@@ -322,7 +325,7 @@ export class PageRootBlockComponent extends BlockComponent<RootBlockModel> {
         parseFloat(paddingLeft),
         parseFloat(paddingRight)
       );
-      if (!isClickOnBlankArea) {
+      if (!isClickOnBlankArea && !this.store.readonly$.value) {
         const lastBlock = notes[notes.length - 1].lastChild();
         if (
           !lastBlock ||