feat(apple): gamepad UI v2 — controller settings + add host, aurora, macOS

Sources reorganized (client: Home/Session/Settings/Stores/Support/Trust; kit:
Audio/Connection/Gamepad/Input/Support/Video/Views) with the big files split
along the same seams.

The gamepad mode is couch-complete, and now on macOS too (the living-room
Mac case), not just iOS/iPadOS:

- GamepadSettingsView: a console-style, fully controller-navigable settings
  screen (X from the launcher) — up/down moves focus, left/right steps values
  (clamped, boundary thud), A cycles/toggles, B closes; the focused row shows a
  one-line description. Backed by GamepadMenuList, the vertical sibling of
  GamepadCarousel, and SettingsOptions — the option lists hoisted out of
  SettingsView statics and shared by the touch, tvOS and gamepad settings.
- GamepadAddHostView + GamepadKeyboard: register a host end to end with a pad
  — field rows open an on-screen controller keyboard (dpad grid, A types,
  X backspaces, B done); the launcher carousel ends in an Add Host tile, so
  the dead-end "add one with touch first" empty state is gone.
- Launcher polish: contextual hint bar with the pad's real button glyphs,
  controller name + battery chip, one shared console chrome.
- GamepadScreenBackground: an animated aurora (TimelineView-driven drifting
  blobs in the brand's violet family, breathing radii, slow hue shift,
  legibility scrim; freezes under Reduce Motion). Pure SwiftUI on purpose — a
  .metal library only bundles reliably in one of the two build systems (SPM vs
  the xcodeproj's synced folders) these sources compile under.
- macOS port: settings/add-host/library present as sized sheets (a macOS sheet
  takes its content's IDEAL size, and the GeometryReader-driven screens
  collapsed to nothing), NSScreen-based mode lists, scroll indicators .never
  (the "always show scroll bars" setting overrides .hidden), tray scrims so
  scrolled rows dim under the pinned title/hints, extra title clearance, and a
  PUNKTFUNK_FORCE_GAMEPAD_UI=1 dev hook — launcher/settings/add-host/keyboard/
  library render-verified live on a real Mac + LAN hosts.
- GamepadMenuInput: X button support, and (re)start now snapshots held buttons
  so a controller handoff press never fires twice (the B that closed the
  keyboard no longer also cancels the screen underneath).
- Cleanups: one "Connection failed" alert in ContentView instead of one per
  home screen; HostDiscovery.advertises/unsaved shared by both home screens.
- host: can_encode_444 stub for the non-Linux/Windows host build (the macOS
  synthetic-source loopback used by the Swift tests).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

clients/apple/README.md

@@ -84,6 +84,17 @@ PUNKTFUNK_AUTOCONNECT=<box-ip> PUNKTFUNK_MODE=1280x720x60 swift run PunktfunkCli
   the two trust flows (TOFU prompt + SPAKE2 `PairSheet`), the stream view with the HUD, a
   tabbed Settings pane (General / Display / Audio / Controllers / Advanced), and the network speed
   test. A Scene-level **Stream** menu carries Disconnect (⌘D) and the HUD toggle (⌘⇧S).
+  On iOS/iPadOS **and macOS** a connected controller swaps the whole home for the **gamepad UI**
+  (`Home/Gamepad*`, `Settings/GamepadSettingsView`): a console-style host carousel (A connect · Y
+  library · X settings), a controller-navigable settings screen, an add-host flow with an
+  on-screen controller keyboard (no touch required anywhere), and the coverflow library browser —
+  all driven by the shared `GamepadMenuInput` poller + `GamepadCarousel`/`GamepadMenuList` focus
+  machinery, with dual-channel haptics (device Taptic + controller `MenuHaptics`), over an
+  animated "aurora" backdrop (`GamepadScreenBackground` — TimelineView-driven drifting color
+  blobs; deliberately pure SwiftUI, since a .metal library only reliably bundles in one of the
+  two build systems these sources compile under). macOS presents the settings/add-host screens as
+  sheets (no `fullScreenCover` there); `PUNKTFUNK_FORCE_GAMEPAD_UI=1` forces the mode without a
+  physical pad (dev/screenshots).
 - **Tests** (`swift test`) — Annex-B units, a real-codec VideoToolbox round trip, DualSense
   trigger-effect and gamepad-wire conversions, loopback integration against real local hosts, and the
   remote first-light test.