fix(css): correct selector for free text editor overlay in PDF viewer CSS (#3916)

# Description of Changes


**What was changed:**  

- The CSS selector in `viewer-redact.css` and `viewer.css` was updated
from
  ```.annotationEditorLayer freeTextEditor .overlay.enabled```  
  to  
  ```.annotationEditorLayer .freeTextEditor .overlay.enabled```  
to properly target the `.freeTextEditor` element under
`.annotationEditorLayer`.

**Why the change was made:**  

- The previous selector was missing the dot before `freeTextEditor`, so
the overlay for free-text annotations was not being displayed as
intended.

---

## Checklist

### General

- [x] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [x] I have read the [Stirling-PDF Developer
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md)
(if applicable)
- [ ] I have read the [How to add new languages to
Stirling-PDF](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md)
(if applicable)
- [ ] I have performed a self-review of my own code
- [ ] My changes generate no new warnings

### Documentation

- [ ] I have updated relevant docs on [Stirling-PDF's doc
repo](https://github.com/Stirling-Tools/Stirling-Tools.github.io/blob/main/docs/)
(if functionality has heavily changed)
- [ ] I have read the section [Add New Translation
Tags](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### UI Changes (if applicable)

- [ ] Screenshots or videos demonstrating the UI changes are attached
(e.g., as comments or direct attachments in the PR)

### Testing (if applicable)

- [ ] I have tested my changes locally. Refer to the [Testing
Guide](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/devGuide/DeveloperGuide.md#6-testing)
for more details.

stirling-pdf/src/main/resources/static/pdfjs-legacy/css/viewer-redact.css

@@ -1838,7 +1838,7 @@
   height: 100%;
 }
 
-.annotationEditorLayer freeTextEditor .overlay.enabled {
+.annotationEditorLayer .freeTextEditor .overlay.enabled {
   display: block;
 }
 

stirling-pdf/src/main/resources/static/pdfjs-legacy/css/viewer.css

@@ -1852,7 +1852,7 @@
   height:100%;
 }
 
-.annotationEditorLayer freeTextEditor .overlay.enabled{
+.annotationEditorLayer .freeTextEditor .overlay.enabled{
   display:block;
 }