Closes [#ISSUE](https://github.com/zed-industries/zed/issues/20696)

Release Notes:

- Hide block cursor text when the cursor is within a redacted range

Screenshot:

<img width="434" height="174" alt="image"
src="https://github.com/user-attachments/assets/5d9dc140-7abe-49a8-823a-58deb0e170dc"
/>