Fix: Ensure window.analyticsPromptBoolean is Defined for Analytics Dialog (#2958)

# Description of Changes

### What was changed
- Added a JavaScript block to correctly initialize
`window.analyticsPromptBoolean` with a Thymeleaf expression.
- Wrapped the script in `/*<![CDATA[*/` and `/*]]>*/` for compatibility
with XHTML.

### Why the change was made
- Previously, `window.analyticsPromptBoolean` was always `undefined`,
preventing the analytics dialog from being displayed correctly.
- This fix ensures that the variable is properly initialized, allowing
the dialog to appear when required.

### Challenges encountered
- Ensuring the Thymeleaf expression is correctly interpreted within the
JavaScript block.

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## 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/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/HowToAddNewLanguage.md)
(if applicable)
- [ ] I have performed a self-review of my own code
- [x] 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/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/DeveloperGuide.md#6-testing)
for more details.