feat(repo): add .gitattributes for cross-platform line ending normalization

Ensures consistent LF line endings in the repository across all platforms.
Critical for shell scripts that execute on Linux CI/CD environments.

Key changes:
- Shell scripts (*.sh) enforce eol=lf to prevent bash interpreter errors
- Rust source and config files normalized to LF
- Binary files explicitly marked to prevent conversion
- Default text=auto provides safe handling for unlisted file types

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

Simplified

.gitattributes

@@ -0,0 +1,33 @@
+# Normalize all text files
+* text=auto
+
+# Force LF for scripts and build-critical files
+*.sh text eol=lf
+Dockerfile* text eol=lf
+*.rs text eol=lf
+*.toml text eol=lf
+*.yml text eol=lf
+*.yaml text eol=lf
+
+# CI
+.github/**/* text eol=lf
+
+# Images
+*.png binary
+*.jpg binary
+*.jpeg binary
+*.gif binary
+*.ico binary
+
+# Archives
+*.zip binary
+*.tar binary
+*.tgz binary
+*.gz binary
+*.7z binary
+
+# Compiled artifacts
+*.so binary
+*.dll binary
+*.exe binary
+*.a binary