chore: remove preview-update debug button, add GDI features, add contributor

- Remove debug "Preview Update Modal" button from Settings/About
- Add Win32_Graphics/Win32_Graphics_Gdi features for taskbar GDI icons
- Add sorensiimSalling contributor credit for Russian translation (PR #140)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/locales/en.ts

@@ -491,7 +491,6 @@ export const enTranslation = {
     aboutLicense: 'License',
     aboutLicenseText: 'GNU GPL v3 — free to use, modify, and distribute under the same license.',
     aboutRepo: 'Source Code on GitHub',
-    aboutPreviewUpdate: 'Preview Update Modal',
     aboutVersion: 'Version',
     aboutBuiltWith: 'Built with Tauri · React · TypeScript · Rust/rodio',
     aboutAiCredit: 'Developed with the support of Claude Code by Anthropic',