feat: camera-restore + LauncherUI UX 개선 + player fallback 강화 (#15)

camera-restore:
- IEngineStateProvider.SetCamera 반사 쓰기 (HmegDirectStateProvider)
- POST /camera/restore (BridgeHttpServer, StateRouter)
- Recorder --sidecar-url + camera_snapshot 캡처
- UiaPlayerHost.TryRestoreCamera, PlayerEngine 재생 전 복원
- 149 tests

LauncherUI (#15):
- Sidecar URL 체크박스 + 입력란 (녹화/재생 모두 연동)
- 재생 속도 슬라이더 (0.25x~4.0x, 기본 1.0x)
- 빌드 타임스탬프 타이틀바 표시
- 녹화 완료 후 RecordNameBox 초기화
- UiAnalysisWindow 추가

PlayerEngine (#15):
- CancellationToken 지원 (중단 버튼 동작)
- Focus 스텝 early return (no-op, issue #11)
- Type/Drag unresolvable UIA path fallback
- SpeedMultiplier 옵션

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/Sut/EgBim/Recordingtest.Sut.EgBim.PluginHost.Tests/StateRouterTests.cs

@@ -13,6 +13,7 @@ public class StateRouterTests
         public CameraSnapshot GetCamera() => new(new double[] { 1, 2, 3 }, new double[] { 0, 0, 0 }, new double[] { 0, 0, 1 }, 45);
         public SceneSnapshot GetScene() => new(7, "doc.hmeg");
         public bool GetRenderComplete() => true;
+        public void SetCamera(CameraSnapshot snapshot) { /* no-op in tests */ }
     }
 
     private sealed class FaultyProvider : IEngineStateProvider
@@ -21,6 +22,7 @@ public class StateRouterTests
         public CameraSnapshot GetCamera() => throw new InvalidOperationException();
         public SceneSnapshot GetScene() => throw new InvalidOperationException();
         public bool GetRenderComplete() => throw new InvalidOperationException();
+        public void SetCamera(CameraSnapshot snapshot) => throw new InvalidOperationException();
     }
 
     [Fact]