style: normalize whitespace and line endings across shell scripts

Clean up inconsistent whitespace formatting in:
- lib/arduino.sh
- install.sh
- lib/packages.sh

lib/packages.sh

@@ -20,4 +20,7 @@ else
   # fd is named differently on Ubuntu
   sudo apt install -y fd-find 2>/dev/null || true
 fi
+
+# Rebuild certificate store so Go/curl pick up system CAs
+sudo update-ca-certificates 2>/dev/null || true
 info "Base packages installed"