fix(editor): adjust highlght style of comment and comment editor flickering (#13040)

### Before


https://github.com/user-attachments/assets/6b98946b-d53c-42fb-b341-e09ba5204523

### After


https://github.com/user-attachments/assets/274341de-33c4-4fd3-b01b-a8f7c25bf2fe



#### PR Dependency Tree


* **PR #13040** 👈

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

* **New Features**
* Improved comment highlighting: Clicking now cycles through and
highlights individual comments one at a time instead of highlighting all
at once.
* Highlighting behavior is now more flexible, allowing highlighting to
be toggled on or off in certain scenarios.

* **Bug Fixes**
* Prevented flickering in the comment editor when focusing on comments.

* **Refactor**
* Enhanced selection and anchoring logic to support the new highlight
flag and updated types for improved clarity and control.

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


#### PR Dependency Tree


* **PR #13040** 👈

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

packages/frontend/core/src/modules/editor/entities/editor.ts

@@ -56,7 +56,7 @@ export class Editor extends Entity {
     const mode = get(this.mode$);
     let id = selector?.blockIds?.[0];
     let commentId = selector?.commentId;
-    let key = 'blockIds';
+    let key: 'blockIds' | 'elementIds' = 'blockIds';
 
     if (mode === 'edgeless') {
       const elementId = selector?.elementIds?.[0];
@@ -195,7 +195,7 @@ export class Editor extends Entity {
   }
 
   handleFocusAt(focusAt: {
-    key: string;
+    key: 'blockIds' | 'elementIds';
     mode: DocMode;
     id?: string;
     commentId?: string;
@@ -208,6 +208,7 @@ export class Editor extends Entity {
 
     let finalId = id;
     let finalKey = key;
+    let highlight = true;
 
     // If we have commentId but no blockId, find the block from the comment
     if (commentId && !id && editorContainer.host?.std) {
@@ -230,6 +231,9 @@ export class Editor extends Entity {
           finalKey = 'blockIds';
         }
       }
+      // Workaround: clear selection to avoid comment editor flickering
+      selection?.clear();
+      highlight = false;
     }
 
     if (mode === this.mode$.value && finalId) {
@@ -237,7 +241,8 @@ export class Editor extends Entity {
         selection?.create(HighlightSelection, {
           mode,
           [finalKey]: [finalId],
-        }),
+          highlight,
+        } as const),
       ]);
     }
   }