Update scripts/build_macos_pkg.sh

Co-authored-by: sourcery-ai[bot] <58596630+sourcery-ai[bot]@users.noreply.github.com>

Author: rhatdan

scripts/build_macos_pkg.sh

@@ -99,8 +99,9 @@ cat > "$SCRIPTS_DIR/postinstall" << 'EOF'
 # Post-installation script for RamaLama
 
 # Ensure /usr/local/bin is in PATH
-if ! grep -q '/usr/local/bin' ~/.zshrc 2>/dev/null; then
-    echo 'export PATH="/usr/local/bin:$PATH"' >> ~/.zshrc
+EXPORT_LINE='export PATH="/usr/local/bin:$PATH"'
+if ! grep -Fxq "$EXPORT_LINE" ~/.zshrc 2>/dev/null; then
+    echo "$EXPORT_LINE" >> ~/.zshrc
 fi
 
 if ! grep -q '/usr/local/bin' ~/.bash_profile 2>/dev/null; then