fix: enforce LF line endings for shell scripts (#183)

* fix: enforce LF line endings for shell scripts via .gitattributes

Prevents CRLF issues when cloning on Windows, which breaks shebangs
and script execution in Docker containers.

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

* fix: enforce LF line endings for Python scripts too

Python scripts with shebangs (e.g. sample-files/gen_demo.py) have the
same CRLF breakage risk as shell scripts on Windows clones.

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

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: NotYuSheng

.gitattributes

@@ -0,0 +1,6 @@
+# Normalize line endings on commit
+* text=auto
+
+# Force LF for scripts with shebangs — CRLF breaks them on Linux/macOS
+*.sh text eol=lf
+*.py text eol=lf