fix: Modal-Titel in HelpTooltip übersetzt

- Modal-Titel verwendet jetzt Übersetzung (Hilfe/Help)
- Browser-Tooltip entfernt (nur noch custom Tooltip)
- useTranslations in HelpTooltip-Komponente integriert

messages/en.json

@@ -278,6 +278,7 @@
       "title": "Curator Help & Manual",
       "backToDashboard": "Back to Dashboard",
       "helpButton": "Help",
+      "modalTitle": "Help",
       "introductionTitle": "Introduction",
       "introductionText": "As a curator, you are responsible for managing songs within your assigned genres and specials. This dashboard allows you to upload, edit, and organize music for the Hördle game.",
       "permissionsTitle": "Your Permissions",