feat(ios): W0 scaffold + day-1 spike + WireProtocol frozen contract + TestSupport doubles

T-iOS-1: ios/ XcodeGen project (iOS 17, Swift 6 strict concurrency, ATS per PLAN §5.2), 5 SPM package shells, CI skeleton
T-iOS-2: Origin spike vs real server — URLSessionWebSocketTask custom Origin CONFIRMED (no Starscream); 16MiB replay + EMSGSIZE(40) errno correction written back to plan
T-iOS-3: WireProtocol frozen contract, 59 tests, 100% line coverage, cross-impl vectors vs src/protocol.ts via tsx
T-iOS-4: FakeTransport/FakeClock/FakeHTTPTransport doubles
Verify: independent agent re-ran all acceptance — 6/6 PASS

ios/App/WebTerm/WebTermApp.swift

@@ -0,0 +1,24 @@
+import SwiftUI
+
+/// T-iOS-1 scaffold: empty-window placeholder. Navigation assembly
+/// (Pairing → SessionList → Terminal) is wired in T-iOS-15.
+@main
+struct WebTermApp: App {
+    var body: some Scene {
+        WindowGroup {
+            HelloPlaceholderView()
+        }
+    }
+}
+
+private struct HelloPlaceholderView: View {
+    var body: some View {
+        VStack(spacing: 12) {
+            Image(systemName: "terminal")
+                .font(.largeTitle)
+            Text("Hello WebTerm")
+                .font(.title2)
+        }
+        .padding()
+    }
+}