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>

Packages/VNCUI/Package.swift

@@ -0,0 +1,24 @@
+// swift-tools-version: 6.0
+import PackageDescription
+
+let package = Package(
+    name: "VNCUI",
+    platforms: [.iOS(.v18), .macOS(.v14)],
+    products: [
+        .library(name: "VNCUI", targets: ["VNCUI"])
+    ],
+    dependencies: [
+        .package(path: "../VNCCore")
+    ],
+    targets: [
+        .target(
+            name: "VNCUI",
+            dependencies: ["VNCCore"]
+        ),
+        .testTarget(
+            name: "VNCUITests",
+            dependencies: ["VNCUI"]
+        )
+    ],
+    swiftLanguageModes: [.v6]
+)