fix(tvos): make EAC3 playback conform to Dolby's guidance

Groundwork for #1300. Establishes the session, buffering and route
handling Dolby's application guide prescribes, and adds the diagnostic
arm needed to find out whether Apple's sample-buffer renderer can carry
Atmos objects at all.

Audio session, per the guide's sequence:

- Adopt the long-form playback profile in one atomic call at app launch
  and activate the session there. The SDK only accepts that policy with
  category Playback, a Default/MoviePlayback/SpokenAudio mode and no
  options, so it cannot be assembled from separate calls.
- Report the resolved rendering mode in the player, hidden unless the
  system resolves it. Apple only resolves it for CarPlay and AirPlay, so
  an unresolved value means unknown, never "not Dolby".

Diagnostics (Apple TV only, Settings > Video Playback > Atmos Output Test):

- Add a sample-buffer arm. It reads the asset with AVAssetReader at
  outputSettings nil and hands the untouched compressed buffers and the
  untouched format description straight to the renderer, with a variant
  that rebuilds the description the way playback builds it. Every
  existing mode went through AVPlayer, so nothing exercised the path
  playback actually uses; this is what tells us whether the renderer or
  our construction is at fault.
- Add an AirPlay route picker. AirPlay is the only route where the system
  resolves the rendering mode and the supported channel layouts, so it is
  what makes those observations reachable at all, and the AVPlayer arms
  now allow external playback so every arm can be compared on the same
  destination.
- Add a session-mode toggle for the one profile difference between the
  guide and previous playback behaviour.
- Report the session profile, supported layouts, both format
  descriptions, the magic cookie and the renderer status, and release the
  session on stop so a failed run cannot contaminate the next one.

Also bumps MPVKit to 1.0.14, which carries the matching audio output
work: the channel layout AVFoundation itself uses for Dolby content, a
renderer-failure observer so the fallback to PCM can actually run, the
prescribed feed ordering and preroll, flush recovery that re-supplies the
discarded audio instead of shifting later audio into its place, and
capability-driven fallback on route and capability changes.

This does not yet fix #1300. Whether the sample-buffer renderer can carry
JOC is still unknown; it removes every difference from the documented
setup that could explain the failure, and gives us the arm to answer it
on real hardware.

lib/i18n/zh.i18n.json

@@ -289,6 +289,15 @@
     "atmosTestRawStreamDescription": "以与播放器内 Atmos 播放完全相同的方式流式传输测试文件。需要测试文件 URL。",
     "atmosTestRawFile": "原始 EAC3 文件",
     "atmosTestRawFileDescription": "以已知长度播放测试文件。需要测试文件 URL。",
+    "atmosTestAsbarNative": "采样缓冲渲染器（原生）",
+    "atmosTestAsbarNativeDescription": "将文件未经改动的压缩音频直接交给系统渲染器。需要测试文件 URL。",
+    "atmosTestAsbarGenerated": "采样缓冲渲染器（重建）",
+    "atmosTestAsbarGeneratedDescription": "相同，但音频描述按播放时的方式重建。需要测试文件 URL。",
+    "atmosTestSessionMode": "使用影片播放会话模式",
+    "atmosTestSessionModeDescription": "关闭时使用 Dolby 文档所述的模式。开启时使用先前的模式。",
+    "atmosTestShowRoutePicker": "选择 AirPlay 输出",
+    "atmosTestHideRoutePicker": "隐藏 AirPlay 输出选择器",
+    "atmosTestRoutePickerDescription": "将测试发送到 AirPlay 接收器。只有 AirPlay 会报告已确定的音频模式。",
     "atmosTestStop": "停止测试",
     "atmosTestUrl": "测试文件 URL",
     "atmosTestUrlDescription": "原始 .ec3 Dolby Atmos 文件的 HTTP URL（例如用 ffmpeg 提取）",
@@ -1344,6 +1353,11 @@
     "audioOutput": "音频输出",
     "performanceOverlay": "性能监控",
     "audioPassthrough": "音频直通",
+    "audioOutputDolbyAtmos": "Dolby Atmos",
+    "audioOutputDolbyAudio": "Dolby Audio",
+    "audioOutputSurround": "环绕声",
+    "audioOutputSpatial": "空间音频",
+    "audioOutputStereo": "立体声",
     "audioNormalization": "响度标准化",
     "audioDownmix": "下混为立体声"
   },