setup.sh: fix curl dependency check for minimal Debian, auto-install curl if missing

deploy/setup.sh

@@ -19,10 +19,16 @@ fi
 # Detect OS
 if ! command -v apt-get &> /dev/null; then
   echo "ERROR: This script requires Debian/Ubuntu."
-  echo "       (yum/dnf support can be added on request)"
   exit 1
 fi
 
+# Ensure curl is available (not installed on minimal Debian)
+if ! command -v curl &> /dev/null; then
+  echo "Installing curl..."
+  apt-get update -qq
+  apt-get install -y -qq curl > /dev/null 2>&1
+fi
+
 # Check for Docker
 DOCKER_INSTALLED=false
 if command -v docker &> /dev/null; then