Add position-based colorful Home shortcut palettes

Colorful shortcut cards now color by grid position instead of shortcut
identity, so colors stay in the same slot when shortcuts are reordered.

Adds a Palette option (Classic default, plus Sunset, Meadow, Berry,
Grape) and a Custom palette with a swatch-list editor (ColorPicker + hex
fields) and a switchable comma-separated text field. Color is resolved
per position and wraps by palette length, wired via a new
homeShortcutColorfulColor environment value and a Color(hex:) extension.

Yattee/Core/Settings/SettingsKey.swift

@@ -65,6 +65,8 @@ enum SettingsKey: String, CaseIterable {
     case homeShortcutVisibility
     case homeShortcutLayout
     case homeShortcutCardStyle
+    case homeShortcutColorfulPalette
+    case homeShortcutCustomPaletteColors
     case homeSectionOrder
     case homeSectionVisibility
     case homeSectionItemsLimit
@@ -137,6 +139,7 @@ enum SettingsKey: String, CaseIterable {
         case .preferredQuality, .cellularQuality, .allowSoftwareDecodedFormats, .macPlayerMode, .listStyle,
              // Home layout — different UI paradigms per platform
              .homeShortcutOrder, .homeShortcutVisibility, .homeShortcutLayout, .homeShortcutCardStyle,
+             .homeShortcutColorfulPalette, .homeShortcutCustomPaletteColors,
              .homeSectionOrder, .homeSectionVisibility, .homeSectionItemsLimit, .homeSectionLayout,
              // Top Shelf — tvOS only
              .topShelfSections,

Yattee/Core/Settings/SettingsManager+Home.swift

@@ -110,6 +110,40 @@ extension SettingsManager {
         }
     }
 
+    /// Palette used by the "colorful" card style. Colors are applied by grid
+    /// position. Default is Classic.
+    var homeShortcutColorfulPalette: HomeShortcutColorfulPalette {
+        get {
+            if let cached = _homeShortcutColorfulPalette { return cached }
+            guard let rawValue = string(for: .homeShortcutColorfulPalette) else {
+                return .classic
+            }
+            return HomeShortcutColorfulPalette(rawValue: rawValue) ?? .classic
+        }
+        set {
+            _homeShortcutColorfulPalette = newValue
+            set(newValue.rawValue, for: .homeShortcutColorfulPalette)
+        }
+    }
+
+    /// User-supplied hex colors for the custom "colorful" palette. Stored as a
+    /// single comma-separated string. Defaults to a starter set of colors.
+    var homeShortcutCustomPaletteColors: [String] {
+        get {
+            if let cached = _homeShortcutCustomPaletteColors { return cached }
+            guard let raw = string(for: .homeShortcutCustomPaletteColors) else {
+                return HomeShortcutColorfulPalette.customStarterColors
+            }
+            let colors = raw.split(separator: ",").map { $0.trimmingCharacters(in: .whitespaces) }.filter { !$0.isEmpty }
+            return colors
+        }
+        set {
+            _homeShortcutCustomPaletteColors = newValue
+            let joined = newValue.map { $0.trimmingCharacters(in: .whitespaces) }.filter { !$0.isEmpty }.joined(separator: ",")
+            set(joined, for: .homeShortcutCustomPaletteColors)
+        }
+    }
+
     /// 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

@@ -109,6 +109,8 @@ final class SettingsManager {
     var _homeShortcutVisibility: [HomeShortcutItem: Bool]?
     var _homeShortcutLayout: HomeShortcutLayout?
     var _homeShortcutCardStyle: HomeShortcutCardStyle?
+    var _homeShortcutColorfulPalette: HomeShortcutColorfulPalette?
+    var _homeShortcutCustomPaletteColors: [String]?
     var _homeSectionOrder: [HomeSectionItem]?
     var _homeSectionVisibility: [HomeSectionItem: Bool]?
     var _homeSectionItemsLimit: Int?
@@ -465,6 +467,8 @@ final class SettingsManager {
         _homeShortcutVisibility = nil
         _homeShortcutLayout = nil
         _homeShortcutCardStyle = nil
+        _homeShortcutColorfulPalette = nil
+        _homeShortcutCustomPaletteColors = nil
         _homeSectionOrder = nil
         _homeSectionVisibility = nil
         _homeSectionItemsLimit = nil