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>

Project.yml

@@ -0,0 +1,39 @@
+name: Screens
+options:
+  bundleIdPrefix: com.example.screens
+  deploymentTarget:
+    iOS: "18.0"
+  developmentLanguage: en
+  xcodeVersion: "16.0"
+settings:
+  base:
+    SWIFT_VERSION: "6.0"
+    SWIFT_STRICT_CONCURRENCY: complete
+    ENABLE_USER_SCRIPT_SANDBOXING: YES
+    CODE_SIGN_STYLE: Automatic
+
+packages:
+  VNCCore:
+    path: Packages/VNCCore
+  VNCUI:
+    path: Packages/VNCUI
+
+targets:
+  Screens:
+    type: application
+    platform: iOS
+    deploymentTarget: "18.0"
+    sources:
+      - path: Screens
+    settings:
+      base:
+        PRODUCT_BUNDLE_IDENTIFIER: com.example.screens
+        PRODUCT_NAME: Screens
+        TARGETED_DEVICE_FAMILY: "1,2"
+        GENERATE_INFOPLIST_FILE: NO
+        INFOPLIST_FILE: Screens/Resources/Info.plist
+    dependencies:
+      - package: VNCCore
+        product: VNCCore
+      - package: VNCUI
+        product: VNCUI