fix(core): editor blur unexpectedly when clicking blank area (#10501)

### Before

https://github.com/user-attachments/assets/3c4b20e1-6d89-4dc7-a51f-04b6e9a89486

### After

https://github.com/user-attachments/assets/86b93403-597e-4dbb-ab65-90908342c230

blocksuite/affine/block-note/src/commands/focus-block-end.ts

@@ -4,14 +4,23 @@ import {
   TextSelection,
 } from '@blocksuite/block-std';
 
+/**
+ * Focus the end of the block
+ * @param focusBlock - The block to focus
+ * @param force - If set to true, the selection will be cleared.
+ * It is useful when the selection is same.
+ */
 export const focusBlockEnd: Command<{
   focusBlock?: BlockComponent;
+  force?: boolean;
 }> = (ctx, next) => {
-  const { focusBlock, std } = ctx;
+  const { focusBlock, force, std } = ctx;
   if (!focusBlock || !focusBlock.model.text) return;
 
   const { selection } = std;
 
+  if (force) selection.clear();
+
   selection.setGroup('note', [
     selection.create(TextSelection, {
       from: {