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/Views/Home/HomeShortcutStyleView.swift

@@ -11,6 +11,23 @@ import SwiftUI
 
 struct HomeShortcutStyleView: View {
     @Binding var style: HomeShortcutCardStyle
+    @Binding var palette: HomeShortcutColorfulPalette
+    @Binding var customColors: [String]
+
+    /// Editing mode for the custom palette.
+    private enum CustomEditMode: String, CaseIterable {
+        case list
+        case text
+
+        var displayName: LocalizedStringKey {
+            switch self {
+            case .list: return "home.shortcuts.palette.custom.mode.list"
+            case .text: return "home.shortcuts.palette.custom.mode.text"
+            }
+        }
+    }
+
+    @State private var customEditMode: CustomEditMode = .list
 
     private let previewColumns = [GridItem(.adaptive(minimum: 150), spacing: 16)]
 
@@ -31,9 +48,17 @@ struct HomeShortcutStyleView: View {
                 #endif
             }
 
+            if style == .colorful {
+                paletteSection
+
+                if palette == .custom {
+                    customColorsSection
+                }
+            }
+
             Section {
                 LazyVGrid(columns: previewColumns, spacing: 16) {
-                    ForEach(previewItems) { item in
+                    ForEach(Array(previewItems.enumerated()), id: \.element.id) { index, item in
                         HomeShortcutCardView(
                             icon: item.icon,
                             title: item.localizedTitle,
@@ -43,6 +68,10 @@ struct HomeShortcutStyleView: View {
                             colorfulColor: item.cardColor,
                             styleOverride: style
                         )
+                        .environment(
+                            \.homeShortcutColorfulColor,
+                            HomeShortcutColorfulPalette.color(forPosition: index, palette: palette, customHex: customColors)
+                        )
                     }
                 }
                 .padding(.vertical, 4)
@@ -60,6 +89,161 @@ struct HomeShortcutStyleView: View {
         #endif
     }
 
+    // MARK: - Palette
+
+    private var paletteSection: some View {
+        Section {
+            Picker(String(localized: "home.settings.shortcuts.palette"), selection: $palette) {
+                ForEach(HomeShortcutColorfulPalette.allCases, id: \.self) { palette in
+                    Text(palette.displayName).tag(palette)
+                }
+            }
+
+            // Swatch strip for the selected palette.
+            swatchStrip(for: paletteSwatchColors)
+                .padding(.vertical, 4)
+        } header: {
+            Text(String(localized: "home.settings.shortcuts.palette"))
+        }
+    }
+
+    /// Colors shown in the selected-palette swatch strip.
+    private var paletteSwatchColors: [Color] {
+        if palette == .custom {
+            let parsed = customColors.compactMap { Color(hex: $0) }
+            return parsed.isEmpty ? (HomeShortcutColorfulPalette.classic.builtInColors ?? []) : parsed
+        }
+        return palette.builtInColors ?? []
+    }
+
+    private func swatchStrip(for colors: [Color]) -> some View {
+        HStack(spacing: 6) {
+            ForEach(Array(colors.enumerated()), id: \.offset) { _, color in
+                RoundedRectangle(cornerRadius: 5)
+                    .fill(color)
+                    .frame(height: 22)
+            }
+        }
+    }
+
+    // MARK: - Custom Colors
+
+    private var customColorsSection: some View {
+        Section {
+            Picker(String(localized: "home.shortcuts.palette.custom.mode"), selection: $customEditMode) {
+                ForEach(CustomEditMode.allCases, id: \.self) { mode in
+                    Text(mode.displayName).tag(mode)
+                }
+            }
+            .pickerStyle(.segmented)
+
+            switch customEditMode {
+            case .list:
+                ForEach(customColors.indices, id: \.self) { index in
+                    customColorRow(index: index)
+                }
+                .onDelete { offsets in
+                    customColors.remove(atOffsets: offsets)
+                }
+
+                Button {
+                    let seed = HomeShortcutColorfulPalette.customStarterColors.first ?? "#4D96FF"
+                    customColors.append(seed)
+                } label: {
+                    Label(String(localized: "home.shortcuts.palette.custom.add"), systemImage: "plus.circle.fill")
+                }
+
+            case .text:
+                TextField(
+                    String(localized: "home.shortcuts.palette.custom.placeholder"),
+                    text: customColorsText,
+                    axis: .vertical
+                )
+                .lineLimit(3 ... 6)
+                #if os(iOS)
+                .textInputAutocapitalization(.characters)
+                .autocorrectionDisabled()
+                #endif
+                .font(.body.monospaced())
+            }
+        } header: {
+            Text(String(localized: "home.shortcuts.palette.custom.header"))
+        } footer: {
+            Text(String(localized: "home.shortcuts.palette.custom.footer"))
+        }
+    }
+
+    private func customColorRow(index: Int) -> some View {
+        HStack(spacing: 12) {
+            ColorPicker("", selection: colorBinding(at: index), supportsOpacity: false)
+                .labelsHidden()
+
+            TextField("#RRGGBB", text: hexBinding(at: index))
+                #if os(iOS)
+                .textInputAutocapitalization(.characters)
+                .autocorrectionDisabled()
+                #endif
+                .font(.body.monospaced())
+
+            Spacer(minLength: 0)
+
+            Button(role: .destructive) {
+                guard customColors.indices.contains(index) else { return }
+                customColors.remove(at: index)
+            } label: {
+                Image(systemName: "minus.circle.fill")
+                    .foregroundStyle(.red)
+            }
+            .buttonStyle(.plain)
+        }
+    }
+
+    // MARK: - Bindings
+
+    /// Two-way binding between a stored hex string and a SwiftUI Color for the
+    /// native ColorPicker.
+    private func colorBinding(at index: Int) -> Binding<Color> {
+        Binding(
+            get: {
+                guard customColors.indices.contains(index) else { return .gray }
+                return Color(hex: customColors[index]) ?? .gray
+            },
+            set: { newColor in
+                guard customColors.indices.contains(index) else { return }
+                customColors[index] = newColor.toHexString()
+            }
+        )
+    }
+
+    /// Editable hex text for a single custom color.
+    private func hexBinding(at index: Int) -> Binding<String> {
+        Binding(
+            get: {
+                guard customColors.indices.contains(index) else { return "" }
+                return customColors[index]
+            },
+            set: { newValue in
+                guard customColors.indices.contains(index) else { return }
+                customColors[index] = newValue
+            }
+        )
+    }
+
+    /// Comma/newline separated hex list for the text-editing mode.
+    private var customColorsText: Binding<String> {
+        Binding(
+            get: { customColors.joined(separator: ", ") },
+            set: { newValue in
+                customColors = newValue
+                    .split(whereSeparator: { $0 == "," || $0 == "\n" })
+                    .map { $0.trimmingCharacters(in: .whitespaces) }
+                    .filter { !$0.isEmpty }
+            }
+        )
+    }
+
+    // MARK: - Preview Helpers
+
     /// Shortcuts without a meaningful count hide it in the filled layout,
     /// mirroring `HomeView`'s real card configuration.
     private func showsCount(for item: HomeShortcutItem) -> Bool {
@@ -89,8 +273,12 @@ struct HomeShortcutStyleView: View {
 
 #Preview {
     NavigationStack {
-        HomeShortcutStyleView(style: .constant(.colorful))
-            .appEnvironment(.preview)
+        HomeShortcutStyleView(
+            style: .constant(.colorful),
+            palette: .constant(.classic),
+            customColors: .constant(HomeShortcutColorfulPalette.customStarterColors)
+        )
+        .appEnvironment(.preview)
     }
 }
 #endif