Feature/v2/landing page upload buttons (#4259)

# Description of Changes

<img width="659" height="453" alt="Screenshot 2025-08-22 at 5 28 53 PM"
src="https://github.com/user-attachments/assets/1dd0f63c-0b08-435c-bb0e-00bd85be7f24"
/>
<img width="968" height="766" alt="Screenshot 2025-08-22 at 5 30 00 PM"
src="https://github.com/user-attachments/assets/86614256-1375-4e6e-b5bb-ae9cb6708135"
/>

---

## Checklist

### General

- [ ] I have read the [Contribution
Guidelines](https://github.com/Stirling-Tools/Stirling-PDF/blob/main/CONTRIBUTING.md)
- [ ] 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.

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

@@ -604,6 +604,10 @@
       "desc": "Build multi-step workflows by chaining together PDF actions. Ideal for recurring tasks."
     }
   },
+  "landing": {
+    "addFiles": "Add Files",
+    "uploadFromComputer": "Upload from computer"
+  },
   "viewPdf": {
     "tags": "view,read,annotate,text,image,highlight,edit",
     "title": "View/Edit PDF",