UI/allow logo selection (#4982)

# Description of Changes

- Allow switching between logos in-app using the same section in
settings

---

## 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)

### 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)

- [ ] 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/src/core/hooks/useLogoVariant.ts

@@ -0,0 +1,18 @@
+import { useMemo } from 'react';
+import { usePreferences } from '@app/contexts/PreferencesContext';
+import { useAppConfig } from '@app/contexts/AppConfigContext';
+import type { LogoVariant } from '@app/services/preferencesService';
+import { ensureLogoVariant } from '@app/constants/logo';
+
+export function useLogoVariant(): LogoVariant {
+  const { preferences } = usePreferences();
+  const { config } = useAppConfig();
+
+  return useMemo(() => {
+    // Check local storage first, then fall back to server config
+    const preferenceVariant = preferences.logoVariant;
+    const configVariant = config?.logoStyle;
+    return ensureLogoVariant(preferenceVariant ?? configVariant);
+  }, [config?.logoStyle, preferences.logoVariant]);
+}
+