chore: add .gitattributes to normalize line endings

.gitattributes

@@ -0,0 +1,39 @@
+# =========================
+# Text files: LF normalized
+# =========================
+* text=auto eol=lf
+
+# =========================
+# Unity / C# / UI Toolkit
+# =========================
+*.cs      text eol=lf
+*.uxml    text eol=lf
+*.uss     text eol=lf
+*.shader  text eol=lf
+*.compute text eol=lf
+*.meta    text eol=lf
+
+# =========================
+# Documentation / Config
+# =========================
+*.md      text eol=lf
+*.txt     text eol=lf
+*.json    text eol=lf
+*.yml     text eol=lf
+*.yaml    text eol=lf
+
+# =========================
+# Binary assets
+# =========================
+*.png     binary
+*.jpg     binary
+*.jpeg    binary
+*.gif     binary
+*.psd     binary
+*.wav     binary
+*.mp3     binary
+*.ogg     binary
+*.ttf     binary
+*.otf     binary
+*.fbx     binary
+*.unity   binary