Extracted the PreviewPreinstalling service in the Sample app target into its own file and declared it as development asset.

Apps/Attendi/Sources/Views/ContentView.swift

@@ -12,7 +12,7 @@ import SwiftUI
 ///
 /// The services attached to the feature, the transcription shown in the sheet, and the notifier owning the notifications live in the view's
 /// ``Model``; the view itself only renders it and forwards the feature's output, the picker's changes, and the sheet's dismissal. All
-/// user-facing text is localized through the app's string catalog.
+/// user-facing text is localized through the app's string catalog, resolved via its generated string symbols.
 struct ContentView: View {
 
     // MARK: Properties
@@ -220,35 +220,6 @@ private enum Constant {
 
 // MARK: - Previews
 
-/// The preinstalling service used by the previews, which resolves every locale as supported and downloads nothing.
-private struct PreviewPreinstalling: Preinstalling {
-
-    /// The stream of events the service emits, which finishes immediately.
-    let events: AsyncStream<PreinstallingEvent> = .init { continuation in
-        continuation.finish()
-    }
-
-    func preinstall(
-        for locale: Locale
-    ) async {
-        // The previews preinstall no speech model assets.
-    }
-
-    func supportedLocale(
-        equivalentTo locale: Locale
-    ) async -> Locale? {
-        locale
-    }
-
-    func supportedLocales() async -> [Locale] {
-        [
-            Locale(identifier: "en-US"),
-            Locale(identifier: "nl-NL"),
-        ]
-    }
-
-}
-
 #Preview(
     "Content view"
 ) {