chore: add .gitattributes to enforce LF line endings

Prevent Windows/WSL editors from rewriting source files to CRLF, which
produced large content-free line-ending diffs. Forces LF for all text
files (text=auto eol=lf) and marks fonts/images as binary.

.gitattributes

@@ -0,0 +1,21 @@
+# Line-ending normalization
+#
+# Force LF for all text files in BOTH the repository and the working tree.
+# This stops Windows/WSL editors from silently rewriting files to CRLF, which
+# otherwise produces large, content-free line-ending diffs (e.g. the whole-file
+# CRLF churn cleaned up on 2026-06-22). The repo standard is LF.
+* text=auto eol=lf
+
+# Binary assets — never apply text/EOL normalization, never diff as text.
+*.woff2 binary
+*.woff  binary
+*.ttf   binary
+*.otf   binary
+*.eot   binary
+*.png   binary
+*.jpg   binary
+*.jpeg  binary
+*.gif   binary
+*.webp  binary
+*.ico   binary
+*.pdf   binary