Phase 0: scaffold

Two SPM packages (VNCCore, VNCUI) + thin iOS app target wired via
xcodegen. Builds for iPhone 17 simulator, unit tests pass.

- VNCCore: SessionState, SessionController stub, Transport protocol
  with DirectTransport (NWConnection), DiscoveryService (Bonjour on
  _rfb._tcp and _workstation._tcp), SavedConnection @Model,
  ConnectionStore, KeychainService, ClipboardBridge
- VNCUI: ConnectionListView, AddConnectionView, SessionView,
  FramebufferView/FramebufferUIView (UIKit CALayer), InputMapper,
  SettingsView; UIKit bits guarded with #if canImport(UIKit) so
  swift test runs on macOS
- App: @main VNCApp, AppStateController state machine, RootView
- RoyalVNCKit dependency pinned to main (transitive CryptoSwift
  constraint blocks tagged releases)
- xcodegen Project.yml + README + .gitignore

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

Screens/App/VNCApp.swift

@@ -0,0 +1,17 @@
+import SwiftUI
+import SwiftData
+import VNCCore
+
+@main
+struct VNCApp: App {
+    @State private var appState = AppStateController()
+
+    var body: some Scene {
+        WindowGroup {
+            RootView()
+                .environment(appState)
+                .task { await appState.initialize() }
+        }
+        .modelContainer(for: SavedConnection.self)
+    }
+}