Move Home shortcut style picker to its own page with live preview

Replace the inline Plain/Accent/Colorful picker in Home customization with
a navigation row that opens a dedicated page. The new page keeps the style
selector and renders a non-interactive preview of every shortcut type so
the chosen style is visible before committing.

- Add an optional styleOverride to HomeShortcutCardView so the preview can
  reflect the not-yet-saved selection.
- On macOS, navigate via navigationDestination(isPresented:) instead of a
  List-embedded NavigationLink, which otherwise stays stuck in its selected
  state after popping back and can't be reopened.

Yattee/Views/Home/HomeShortcutStyleView.swift

@@ -0,0 +1,96 @@
+//
+//  HomeShortcutStyleView.swift
+//  Yattee
+//
+//  Dedicated page for choosing the Home shortcut card style, with a live
+//  non-interactive preview of every shortcut type in the selected style.
+//
+
+#if !os(tvOS)
+import SwiftUI
+
+struct HomeShortcutStyleView: View {
+    @Binding var style: HomeShortcutCardStyle
+
+    private let previewColumns = [GridItem(.adaptive(minimum: 150), spacing: 16)]
+
+    /// All static shortcut types, previewed regardless of the user's current
+    /// Home configuration so every style variation is visible.
+    private let previewItems = HomeShortcutItem.defaultOrder
+
+    var body: some View {
+        List {
+            Section {
+                Picker(String(localized: "home.settings.shortcuts.style"), selection: $style) {
+                    ForEach(HomeShortcutCardStyle.allCases, id: \.self) { style in
+                        Text(style.displayName).tag(style)
+                    }
+                }
+                #if os(iOS)
+                .pickerStyle(.segmented)
+                #endif
+            }
+
+            Section {
+                LazyVGrid(columns: previewColumns, spacing: 16) {
+                    ForEach(previewItems) { item in
+                        HomeShortcutCardView(
+                            icon: item.icon,
+                            title: item.localizedTitle,
+                            count: sampleCount(for: item),
+                            subtitle: "",
+                            showsCount: showsCount(for: item),
+                            colorfulColor: item.cardColor,
+                            styleOverride: style
+                        )
+                    }
+                }
+                .padding(.vertical, 4)
+                .allowsHitTesting(false)
+            } header: {
+                Text(String(localized: "home.settings.shortcuts.style.preview"))
+            }
+        }
+        #if os(macOS)
+        .listStyle(.inset)
+        #endif
+        .navigationTitle(String(localized: "home.settings.shortcuts.style"))
+        #if os(iOS)
+        .navigationBarTitleDisplayMode(.inline)
+        #endif
+    }
+
+    /// Shortcuts without a meaningful count hide it in the filled layout,
+    /// mirroring `HomeView`'s real card configuration.
+    private func showsCount(for item: HomeShortcutItem) -> Bool {
+        switch item {
+        case .openURL, .remoteControl, .subscriptions:
+            return false
+        default:
+            return true
+        }
+    }
+
+    /// Representative count so the accent/colorful (Reminders-style) layout
+    /// looks realistic in the preview.
+    private func sampleCount(for item: HomeShortcutItem) -> Int {
+        switch item {
+        case .playlists: return 8
+        case .bookmarks: return 12
+        case .continueWatching: return 3
+        case .history: return 42
+        case .downloads: return 5
+        case .channels: return 24
+        case .mediaSources: return 2
+        default: return 0
+        }
+    }
+}
+
+#Preview {
+    NavigationStack {
+        HomeShortcutStyleView(style: .constant(.colorful))
+            .appEnvironment(.preview)
+    }
+}
+#endif