Added new localized strings to `Model.en.resx`, `Model.fr-FR.resx`,
and `Model.resx` for additional features/settings in English,
French, and German. Updated `SenderEditorPage.razor` to inject
`ModelLocalizer` and modified the `L` function to prioritize
localized strings from `ModelLocalizer` over `UiLocalizer`.
Included `@using EnvelopeGenerator.Domain.Resources` to ensure
access to the `Model` resource file. These changes improve
localization flexibility and maintainability.
Changed 'SignatureConfirmed' value in English to "Finalization confirmed" and in German to "Abschluss bestätigt". Updated designer file comments to match new wording.
Switched Model.Designer.cs comments from German to English and added new resource string properties for read confirmation workflows. Updated Model.resx and Model.en.resx with new and corrected entries, improved translation consistency, and clarified documentation.
