feat(ios): ship iOS SwiftUI client (VoiceCatiOS)

Full SwiftUI app at clients/apple/iOS/VoiceCatiOS.xcodeproj:
- 24 Swift source files: AppState + SessionState (@Observable @MainActor),
  AudioSessionManager (AVAudioSession owner + interruption/route handling),
  ServerListStore/SavedServer (App Group container + Keychain sharing),
  and 14 SwiftUI views covering the full feature set
- NavigationSplitView on iPad, TabView on iPhone (horizontalSizeClass)
- Channel tree via OutlineGroup, user list with context menu admin actions
- PTT via DragGesture(minimumDistance: 0) + @GestureState
- onEvent closures hop to MainActor via Task { @MainActor in ... }
- App Group: group.cat.voice.VoiceCat (shared with future ReplayKit extension)

C ABI: add vc_audio_suspend / vc_audio_resume (AudioEngine::suspend/resume)
called by AudioSessionManager on AVAudioSession interruption events.

XCFramework: add ios-arm64 and ios-arm64-simulator slices to build-xcframework.sh;
Package.swift gains .iOS(.v17) platform; CMakePresets.json adds apple-ios /
apple-ios-sim presets with arm64-ios / arm64-ios-simulator vcpkg triplets.

Verified: xcodebuild -target VoiceCatiOS -sdk iphonesimulator26.5 BUILD SUCCEEDED.

clients/apple/iOS/VoiceCatiOS/Views/PermissionsView.swift

@@ -0,0 +1,63 @@
+import SwiftUI
+import VoiceCatCore
+
+struct PermissionsView: View {
+    let user: User
+    @Bindable var session: SessionState
+    @Environment(\.dismiss) private var dismiss
+
+    @State private var canCreateTempChannel = false
+    @State private var canKick = false
+    @State private var canBan = false
+    @State private var canMoveUsers = false
+    @State private var canAdminAccounts = false
+    @State private var isAdmin = false
+
+    var body: some View {
+        NavigationStack {
+            Form {
+                Section("Permissions for \(user.nickname)") {
+                    Toggle("Create Temp Channels", isOn: $canCreateTempChannel)
+                        .accessibilityLabel("Can create temporary channels")
+                    Toggle("Kick Users", isOn: $canKick)
+                        .accessibilityLabel("Can kick users")
+                    Toggle("Ban Users", isOn: $canBan)
+                        .accessibilityLabel("Can ban users")
+                    Toggle("Move Users", isOn: $canMoveUsers)
+                        .accessibilityLabel("Can move users between channels")
+                    Toggle("Manage Accounts", isOn: $canAdminAccounts)
+                        .accessibilityLabel("Can manage server accounts")
+                }
+
+                Section {
+                    Toggle("Administrator", isOn: $isAdmin)
+                        .foregroundStyle(isAdmin ? .orange : .primary)
+                        .accessibilityLabel("Full administrator access")
+                } footer: {
+                    Text("Administrators bypass all permission checks.")
+                        .font(.caption)
+                }
+            }
+            .navigationTitle("Permissions")
+            .navigationBarTitleDisplayMode(.inline)
+            .toolbar {
+                ToolbarItem(placement: .cancellationAction) {
+                    Button("Cancel") { dismiss() }
+                }
+                ToolbarItem(placement: .confirmationAction) {
+                    Button("Save") {
+                        let perms = Permissions(
+                            canCreateTempChannel: canCreateTempChannel,
+                            canKick: canKick,
+                            canBan: canBan,
+                            canMoveUsers: canMoveUsers,
+                            canAdminAccounts: canAdminAccounts,
+                            isAdmin: isAdmin)
+                        session.setPermissions(user.id, perms: perms)
+                        dismiss()
+                    }
+                }
+            }
+        }
+    }
+}