Add .gitattributes to enforce LF line endings for shell scripts

This fixes issues when running scripts in WSL where CRLF line endings
cause 'No such file or directory' errors. Also add a fix_line_endings.sh
script for users who already have the wrong line endings.

.gitattributes

@@ -0,0 +1,2 @@
+# Ensure shell scripts always use LF line endings
+*.sh text eol=lf

scripts/fix_line_endings.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+# Fix line endings for coverage scripts
+
+echo "Fixing line endings for coverage scripts..."
+
+# Convert CRLF to LF
+dos2unix scripts/measure_coverage.sh 2>/dev/null || sed -i 's/\r$//' scripts/measure_coverage.sh
+dos2unix scripts/generate_coverage_html.sh 2>/dev/null || sed -i 's/\r$//' scripts/generate_coverage_html.sh
+
+# Ensure execute permissions
+chmod +x scripts/measure_coverage.sh
+chmod +x scripts/generate_coverage_html.sh
+
+echo "Done! Line endings fixed and execute permissions set."
+echo ""
+echo "You can now run:"
+echo "  make coverage-report"
+echo "  make coverage-html"