v0.4.0 — Phase β-3 Editor

Voller Editor-Flow für Decks und 5 Card-Types (basic, basic-reverse,
cloze, typing, multiple-choice). image-occlusion + audio-front kommen
mit β-4 (Media). Anki-Import bleibt vorerst aus (Web parsed client-
side, gibt keinen Server-Import-Endpoint zu rufen).

- DeckCreateBody/UpdateBody, CardCreateBody/UpdateBody Encodable
  mit snake_case-CodingKeys, nil-Felder werden weggelassen
- CardFieldsBuilder mit Type-spezifischen Pflicht-Feld-Konstruktoren
- CardsAPI: createDeck/updateDeck/deleteDeck +
  createCard/updateCard/deleteCard
- DeckEditorView (Create + Edit in einer View): Color-Picker mit
  8-Preset-Palette, Category-Picker (11 Kats, deutsche Labels),
  Visibility-Segmented-Control
- CardEditorView mit Type-Picker und dynamischen Feldern je Typ.
  Cloze-Sektion zeigt Live-Cluster-Count und Hint-Syntax-Hinweis.
  image-occlusion/audio-front zeigen β-4-Placeholder
- DeckDetailView mit Action-Buttons (Lernen, Karte hinzufügen,
  Bearbeiten, Löschen mit Confirmation)
- DeckListView: "+"-Button im Toolbar (Leading) für Create-Sheet
- 7 neue Encoding-Tests (24 Unit-Tests + 1 UI-Test grün)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Sources/Features/Editor/DeckEditorView.swift

@@ -0,0 +1,187 @@
+import ManaCore
+import SwiftUI
+
+/// Deck-Create und Deck-Edit in einer View. `existing == nil` → Create-
+/// Modus mit "Erstellen"-Button. Sonst Edit-Modus mit "Speichern".
+struct DeckEditorView: View {
+    enum Mode: Sendable {
+        case create
+        case edit(deckId: String)
+    }
+
+    let mode: Mode
+    let onSaved: (Deck) -> Void
+
+    @Environment(AuthClient.self) private var auth
+    @Environment(\.dismiss) private var dismiss
+
+    @State private var name: String
+    @State private var description: String
+    @State private var color: String
+    @State private var category: DeckCategory?
+    @State private var visibility: DeckVisibility
+    @State private var isSubmitting = false
+    @State private var errorMessage: String?
+
+    /// Vorgefüllte Farbpalette aus dem forest-Theme. User können
+    /// freie Hex-Werte später via Picker setzen (β-3-extension).
+    private static let presetColors: [String] = [
+        "#10803D", // forest primary light
+        "#1E3A2F", // forest dark
+        "#D97706", // amber
+        "#DC2626", // red
+        "#2563EB", // blue
+        "#7C3AED", // violet
+        "#0D9488", // teal
+        "#737373", // neutral
+    ]
+
+    init(mode: Mode, existing: CachedDeck? = nil, onSaved: @escaping (Deck) -> Void) {
+        self.mode = mode
+        self.onSaved = onSaved
+        _name = State(initialValue: existing?.name ?? "")
+        _description = State(initialValue: existing?.deckDescription ?? "")
+        _color = State(initialValue: existing?.color ?? Self.presetColors[0])
+        _category = State(initialValue: existing?.category)
+        _visibility = State(initialValue: DeckVisibility(rawValue: existing?.visibilityRaw ?? "private") ?? .private)
+    }
+
+    var body: some View {
+        Form {
+            Section("Name") {
+                TextField("Deck-Name", text: $name)
+                    .textInputAutocapitalization(.sentences)
+            }
+
+            Section("Beschreibung") {
+                TextField("optional", text: $description, axis: .vertical)
+                    .lineLimit(2 ... 4)
+            }
+
+            Section("Farbe") {
+                ScrollView(.horizontal, showsIndicators: false) {
+                    HStack(spacing: 10) {
+                        ForEach(Self.presetColors, id: \.self) { hex in
+                            colorSwatch(hex)
+                        }
+                    }
+                    .padding(.vertical, 4)
+                }
+            }
+
+            Section("Kategorie") {
+                Picker("Kategorie", selection: $category) {
+                    Text("Keine").tag(DeckCategory?.none)
+                    ForEach(DeckCategory.allCases, id: \.self) { cat in
+                        Text(cat.label).tag(DeckCategory?.some(cat))
+                    }
+                }
+            }
+
+            Section("Sichtbarkeit") {
+                Picker("Sichtbarkeit", selection: $visibility) {
+                    Text("Privat").tag(DeckVisibility.private)
+                    Text("Space").tag(DeckVisibility.space)
+                    Text("Öffentlich").tag(DeckVisibility.public)
+                }
+                .pickerStyle(.segmented)
+            }
+
+            if let errorMessage {
+                Section {
+                    Text(errorMessage)
+                        .font(.footnote)
+                        .foregroundStyle(CardsTheme.error)
+                }
+            }
+        }
+        .navigationTitle(isCreate ? "Neues Deck" : "Deck bearbeiten")
+        #if os(iOS)
+            .navigationBarTitleDisplayMode(.inline)
+        #endif
+            .toolbar {
+                ToolbarItem(placement: .cancellationAction) {
+                    Button("Abbrechen") { dismiss() }
+                }
+                ToolbarItem(placement: .confirmationAction) {
+                    Button(isCreate ? "Erstellen" : "Speichern") {
+                        Task { await submit() }
+                    }
+                    .disabled(name.trimmingCharacters(in: .whitespaces).isEmpty || isSubmitting)
+                }
+            }
+    }
+
+    private var isCreate: Bool {
+        if case .create = mode { return true }
+        return false
+    }
+
+    @ViewBuilder
+    private func colorSwatch(_ hex: String) -> some View {
+        let isSelected = color == hex
+        Circle()
+            .fill(Color.swatchFromHex(hex))
+            .frame(width: 36, height: 36)
+            .overlay(
+                Circle()
+                    .stroke(isSelected ? CardsTheme.foreground : CardsTheme.border, lineWidth: isSelected ? 3 : 1)
+            )
+            .onTapGesture { color = hex }
+    }
+
+    private func submit() async {
+        isSubmitting = true
+        errorMessage = nil
+        defer { isSubmitting = false }
+        let api = CardsAPI(auth: auth)
+
+        do {
+            switch mode {
+            case .create:
+                let body = DeckCreateBody(
+                    name: name.trimmingCharacters(in: .whitespaces),
+                    description: nonEmpty(description),
+                    color: color,
+                    category: category,
+                    visibility: visibility
+                )
+                let deck = try await api.createDeck(body)
+                onSaved(deck)
+                dismiss()
+            case let .edit(deckId):
+                let body = DeckUpdateBody(
+                    name: name.trimmingCharacters(in: .whitespaces),
+                    description: nonEmpty(description),
+                    color: color,
+                    category: category,
+                    visibility: visibility
+                )
+                let deck = try await api.updateDeck(id: deckId, body: body)
+                onSaved(deck)
+                dismiss()
+            }
+        } catch {
+            errorMessage = (error as? LocalizedError)?.errorDescription ?? String(describing: error)
+        }
+    }
+
+    private func nonEmpty(_ s: String) -> String? {
+        let trimmed = s.trimmingCharacters(in: .whitespaces)
+        return trimmed.isEmpty ? nil : trimmed
+    }
+}
+
+extension Color {
+    static func swatchFromHex(_ hex: String) -> Color {
+        var trimmed = hex.trimmingCharacters(in: .whitespacesAndNewlines)
+        if trimmed.hasPrefix("#") { trimmed = String(trimmed.dropFirst()) }
+        guard let rgb = UInt32(trimmed, radix: 16) else {
+            return CardsTheme.primary
+        }
+        let r = Double((rgb >> 16) & 0xFF) / 255.0
+        let g = Double((rgb >> 8) & 0xFF) / 255.0
+        let b = Double(rgb & 0xFF) / 255.0
+        return Color(red: r, green: g, blue: b)
+    }
+}