fix(screenshots): pin the shot palette — a reused device's saved choice shipped a sunset Apple TV set

The aurora screens read the LIVE uiPalette default, and shot mode never
forced one: the Apple TV Simulator had a sunset palette persisted from
manual use, so every tvOS capture came out pink-on-pale while the iPhone
set stayed violet. ScreenshotHostView now pins the palette (violet, or
PUNKTFUNK_SHOT_PALETTE) before the scene mounts.

Also documents the local tvOS-SIMULATOR wall in screenshots.sh: Xcode
26.6 and the 27 beta plan the macro targets swiftui-navigation-transitions
pulls in for the tvOS triple and never schedule their swift-syntax deps
('unable to resolve module dependency') — prebuilts on or off. Only the
tvOS target links that package, which is why iOS and device builds never
hit it. Local workaround, since HomeView's use is canImport-guarded:
temporarily unlink the product from the tvOS target, capture, restore.

clients/apple/Sources/PunktfunkClient/Screenshots/ScreenshotHost.swift

@@ -16,6 +16,7 @@
 // can wait for layout instead of guessing with a fixed sleep.
 
 #if DEBUG
+import PunktfunkKit
 import SwiftUI
 #if os(macOS)
 import AppKit
@@ -43,6 +44,17 @@ enum ScreenshotMode {
 /// readiness ping for the capture script.
 struct ScreenshotHostView: View {
     let scene: ShotScene
+
+    init(scene: ShotScene) {
+        self.scene = scene
+        // Pin the palette for the capture. The aurora screens read the LIVE `uiPalette` default,
+        // and a reused Simulator (or a dev Mac) carries whatever was last picked there — the
+        // Apple TV set once shipped out on a sunset palette that a test device had persisted.
+        // Idempotent, and only ever runs in shot mode (this view exists behind that gate).
+        UserDefaults.standard.set(
+            ProcessInfo.processInfo.environment["PUNKTFUNK_SHOT_PALETTE"] ?? "violet",
+            forKey: DefaultsKey.uiPalette)
+    }
     #if os(iOS)
     @Environment(\.horizontalSizeClass) private var hSizeClass
     @Environment(\.verticalSizeClass) private var vSizeClass

clients/apple/tools/screenshots.sh

@@ -142,6 +142,14 @@ shoot_sim() {
   # incremental build instead of cold-building into a throwaway tmpdir — CI pins this
   # (apple.yml); local runs keep the self-cleaning mktemp default.
   local dd; dd="${PF_SHOT_DERIVED_DATA:-$(mktemp -d)}"; mkdir -p "$dd"
+  # tvOS-SIMULATOR trap (Xcode 26.6 and the 27 beta, local only so far): the build planner
+  # schedules the SwiftPM MACRO plugin targets that swiftui-navigation-transitions pulls in
+  # (OnceMacro/SwizzlingMacro/AssociationMacro) for the *tvOS* triple and never plans their
+  # swift-syntax dependencies at all — "unable to resolve module dependency: 'SwiftSyntax'".
+  # Device archives and iOS builds don't hit it (only the tvOS target links that package), and
+  # prebuilt-vs-source swift-syntax makes no difference. Until Xcode fixes the planner, the
+  # workaround is temporarily unlinking SwiftUINavigationTransitions from the tvOS target
+  # (HomeView's use is canImport-guarded — the push transition degrades to the crossfade).
   xcodebuild -project Punktfunk.xcodeproj -scheme "$scheme" -configuration Debug \
     -sdk "$sdk" -destination "id=$udid" -derivedDataPath "$dd" \
     CODE_SIGNING_ALLOWED=NO build >/dev/null \