chore: normalize line endings via .gitattributes

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: Toilettrauma

.gitattributes

@@ -0,0 +1,19 @@
+# Line endings are not content. This repo is worked on from both Windows and macOS, and
+# without this a checkout that picks up CRLF reports every file as rewritten — whole-file
+# diffs that bury the real change. Git decides text vs binary; every text file is stored
+# and checked out as LF.
+* text=auto eol=lf
+
+# The exception: Windows shells genuinely want CRLF.
+*.bat text eol=crlf
+*.cmd text eol=crlf
+*.ps1 text eol=crlf
+
+# Assets — byte-for-byte, never converted.
+*.png binary
+*.jpg binary
+*.jpeg binary
+*.gif binary
+*.ico binary
+*.pdf binary
+*.zip binary