Add game center, per-model shuffle, audio focus fixes, README, tests

- README.md with build/architecture overview
- Game Center screen with at-bat timeline, pitch sequence, spray chart,
  and strike zone component views
- VideoShuffle service: per-model bucketed random selection with
  no-back-to-back guarantee; replaces flat shuffle-bag approach
- Refresh JWT token for authenticated NSFW feed; add josie-hamming-2
  and dani-speegle-2 to the user list
- MultiStreamView audio focus: remove redundant isMuted writes during
  startStream and playNextWerkoutClip so audio stops ducking during
  clip transitions; gate AVAudioSession.setCategory(.playback) behind
  a one-shot flag
- GamesViewModel.attachPlayer: skip mute recalculation when the same
  player is re-attached (prevents toggle flicker on item replace)
- mlbTVOSTests target wired through project.yml with
  GENERATE_INFOPLIST_FILE; VideoShuffleTests covers groupByModel,
  pickRandomFromBuckets, real-distribution no-back-to-back invariant,
  and uniform model distribution over 6000 picks

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

mlbTVOS/Views/GameListView.swift

@@ -77,6 +77,8 @@ struct StreamOptionsSheet: View {
                     .padding(.vertical, 18)
                     .background(panelBackground)
                 }
+
+                GameCenterView(game: game)
             }
             .padding(.horizontal, horizontalPadding)
             .padding(.vertical, verticalPadding)
@@ -129,8 +131,6 @@ struct StreamOptionsSheet: View {
                 .padding(22)
                 .background(panelBackground)
             }
-
-            GameCenterView(game: game)
         }
     }