Add card style option for Home shortcut cards

Adds a Style picker (Plain / Accent / Colorful) to the Customize Home
sheet, shown when the shortcuts layout is Cards. Defaults to Plain.

- Plain: current look (light accent tint + accent border)
- Accent: solid accent fill, white icon/text
- Colorful: solid fill with a fixed color per shortcut type

The filled styles use a Reminders-style layout (icon top-leading, count
top-trailing, title anchored to the bottom) with a subtle gradient sheen
over the fill color. Cards without a meaningful count (Open Link, Remote,
Subscriptions, instance content, media sources) hide the number; Remote
shows its status dot in the top-right slot instead.

Persisted via SettingsKey.homeShortcutCardStyle, mirroring the existing
homeShortcutLayout accessor.

Yattee/Core/Settings/SettingsKey.swift

@@ -64,6 +64,7 @@ enum SettingsKey: String, CaseIterable {
     case homeShortcutOrder
     case homeShortcutVisibility
     case homeShortcutLayout
+    case homeShortcutCardStyle
     case homeSectionOrder
     case homeSectionVisibility
     case homeSectionItemsLimit
@@ -135,7 +136,7 @@ enum SettingsKey: String, CaseIterable {
         switch self {
         case .preferredQuality, .cellularQuality, .allowSoftwareDecodedFormats, .macPlayerMode, .listStyle,
              // Home layout — different UI paradigms per platform
-             .homeShortcutOrder, .homeShortcutVisibility, .homeShortcutLayout,
+             .homeShortcutOrder, .homeShortcutVisibility, .homeShortcutLayout, .homeShortcutCardStyle,
              .homeSectionOrder, .homeSectionVisibility, .homeSectionItemsLimit, .homeSectionLayout,
              // Top Shelf — tvOS only
              .topShelfSections,

Yattee/Core/Settings/SettingsManager+Home.swift

@@ -95,6 +95,21 @@ extension SettingsManager {
         }
     }
 
+    /// Visual style for home shortcut cards (plain, accent-filled, or colorful). Default is plain.
+    var homeShortcutCardStyle: HomeShortcutCardStyle {
+        get {
+            if let cached = _homeShortcutCardStyle { return cached }
+            guard let rawValue = string(for: .homeShortcutCardStyle) else {
+                return .plain
+            }
+            return HomeShortcutCardStyle(rawValue: rawValue) ?? .plain
+        }
+        set {
+            _homeShortcutCardStyle = newValue
+            set(newValue.rawValue, for: .homeShortcutCardStyle)
+        }
+    }
+
     /// Layout mode for home sections (list or grid). Default is list on iOS/macOS, grid on tvOS.
     var homeSectionLayout: HomeSectionLayout {
         get {

Yattee/Core/SettingsManager.swift

@@ -108,6 +108,7 @@ final class SettingsManager {
     var _homeShortcutOrder: [HomeShortcutItem]?
     var _homeShortcutVisibility: [HomeShortcutItem: Bool]?
     var _homeShortcutLayout: HomeShortcutLayout?
+    var _homeShortcutCardStyle: HomeShortcutCardStyle?
     var _homeSectionOrder: [HomeSectionItem]?
     var _homeSectionVisibility: [HomeSectionItem: Bool]?
     var _homeSectionItemsLimit: Int?
@@ -463,6 +464,7 @@ final class SettingsManager {
         _homeShortcutOrder = nil
         _homeShortcutVisibility = nil
         _homeShortcutLayout = nil
+        _homeShortcutCardStyle = nil
         _homeSectionOrder = nil
         _homeSectionVisibility = nil
         _homeSectionItemsLimit = nil