feat: SongCreator 씬 완성 — Beat Sage URL 지원, info.dat 메타데이터 자동 추출

- BeatSageUploader: audio_url 지원(UploadFromUrl), PollAndDownload 공통화, ZIP 500 오류 3회 재시도
- BeatSageConverter: info.dat 파싱(SongMetadata), BPM 자동 감지 → 노트 타이밍 변환에 적용
- SongCreatorManager: title/BPM 필수 입력 제거, 난이도 4개 자동 선택, GenerateFlowFromUrl 버그 수정
- NasPublisher: audioPath null 허용(URL 흐름에서 로컬 파일 없는 경우 스킵)
- .gitignore/.gitattributes 초기 설정

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

Assets/TextMesh Pro/Shaders/TMPro_Properties.cginc

@@ -0,0 +1,80 @@
+// UI Editable properties
+uniform sampler2D	_FaceTex;					// Alpha : Signed Distance
+uniform float		_FaceUVSpeedX;
+uniform float		_FaceUVSpeedY;
+uniform fixed4		_FaceColor;					// RGBA : Color + Opacity
+uniform float		_FaceDilate;				// v[ 0, 1]
+uniform float		_OutlineSoftness;			// v[ 0, 1]
+
+uniform sampler2D	_OutlineTex;				// RGBA : Color + Opacity
+uniform float		_OutlineUVSpeedX;
+uniform float		_OutlineUVSpeedY;
+uniform fixed4		_OutlineColor;				// RGBA : Color + Opacity
+uniform float		_OutlineWidth;				// v[ 0, 1]
+
+uniform float		_Bevel;						// v[ 0, 1]
+uniform float		_BevelOffset;				// v[-1, 1]
+uniform float		_BevelWidth;				// v[-1, 1]
+uniform float		_BevelClamp;				// v[ 0, 1]
+uniform float		_BevelRoundness;			// v[ 0, 1]
+
+uniform sampler2D	_BumpMap;					// Normal map
+uniform float		_BumpOutline;				// v[ 0, 1]
+uniform float		_BumpFace;					// v[ 0, 1]
+
+uniform samplerCUBE	_Cube;						// Cube / sphere map
+uniform fixed4 		_ReflectFaceColor;			// RGB intensity
+uniform fixed4		_ReflectOutlineColor;
+//uniform float		_EnvTiltX;					// v[-1, 1]
+//uniform float		_EnvTiltY;					// v[-1, 1]
+uniform float3      _EnvMatrixRotation;
+uniform float4x4	_EnvMatrix;
+
+uniform fixed4		_SpecularColor;				// RGB intensity
+uniform float		_LightAngle;				// v[ 0,Tau]
+uniform float		_SpecularPower;				// v[ 0, 1]
+uniform float		_Reflectivity;				// v[ 5, 15]
+uniform float		_Diffuse;					// v[ 0, 1]
+uniform float		_Ambient;					// v[ 0, 1]
+
+uniform fixed4		_UnderlayColor;				// RGBA : Color + Opacity
+uniform float		_UnderlayOffsetX;			// v[-1, 1]
+uniform float		_UnderlayOffsetY;			// v[-1, 1]
+uniform float		_UnderlayDilate;			// v[-1, 1]
+uniform float		_UnderlaySoftness;			// v[ 0, 1]
+
+uniform fixed4 		_GlowColor;					// RGBA : Color + Intesity
+uniform float 		_GlowOffset;				// v[-1, 1]
+uniform float 		_GlowOuter;					// v[ 0, 1]
+uniform float 		_GlowInner;					// v[ 0, 1]
+uniform float 		_GlowPower;					// v[ 1, 1/(1+4*4)]
+
+// API Editable properties
+uniform float 		_ShaderFlags;
+uniform float		_WeightNormal;
+uniform float		_WeightBold;
+
+uniform float		_ScaleRatioA;
+uniform float		_ScaleRatioB;
+uniform float		_ScaleRatioC;
+
+uniform float		_VertexOffsetX;
+uniform float		_VertexOffsetY;
+
+//uniform float		_UseClipRect;
+uniform float		_MaskID;
+uniform sampler2D	_MaskTex;
+uniform float4		_MaskCoord;
+uniform float4		_ClipRect;	// bottom left(x,y) : top right(z,w)
+uniform float		_MaskSoftnessX;
+uniform float		_MaskSoftnessY;
+
+// Font Atlas properties
+uniform sampler2D	_MainTex;
+uniform float		_TextureWidth;
+uniform float		_TextureHeight;
+uniform float 		_GradientScale;
+uniform float		_ScaleX;
+uniform float		_ScaleY;
+uniform float		_PerspectiveFilter;
+uniform float		_Sharpness;