update to add optional Zero Padding to page numbers (Bates Stamping).… (#5612)

… Useful in legal and other professional fields to have page numbers
written with padded 0s of a fixed width. This is also known as bates
stamping.

# Description of Changes

<!--
Another category is added to the add page number tool where it allows
for defining a 0 padded format. If left as 0, it will not added padded
0s and will be the current implementation.
-->

---

## 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)
- [x] 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)
- [x] 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/devGuide/HowToAddNewLanguage.md#add-new-translation-tags)
(for new translation tags only)

### Translations (if applicable)

- [ ] I ran
[`scripts/counter_translation.py`](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/docs/counter_translation.md)

### 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)

- [x] 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.

---------

Co-authored-by: Anthony Stirling <[email protected]>

frontend/public/locales/en-GB/translation.toml

@@ -219,6 +219,9 @@ pagesAndStarting = "Pages & Starting Number"
 positionAndPages = "Position & Pages"
 preview = "Position Selection"
 previewDisclaimer = "Preview is approximate. Final output may vary due to PDF font metrics."
+zeroPad = "Zero‑pad Width (Bates Stamping)"
+zeroPadTooltip = "Zero‑pad (Bates Stamp) page numbers to this width (e.g., 3 ⇒ 001). Set 0 to disable."
+
 
 [addPageNumbers.selectText]
 1 = "Select PDF file:"