fix(runner): install Node.js 20 on host before starting runner (required for JS actions in host mode)

install.sh

@@ -755,8 +755,21 @@ do_forgejo_runner_install() {
     install_deps
     echo ""
 
+    # --- Node.js 20 (required for JS-based actions in host mode) ---
+    log_step "Checking Node.js..."
+    if node --version 2>/dev/null | grep -q "^v2"; then
+        log_ok "Node.js $(node --version) already installed."
+    else
+        log_step "Installing Node.js 20 LTS..."
+        curl -fsSL https://deb.nodesource.com/setup_20.x | bash - > /dev/null 2>&1
+        apt-get install -y nodejs > /dev/null 2>&1
+        log_ok "Node.js $(node --version) installed."
+    fi
+    echo ""
+
     if docker ps -a --format '{{.Names}}' | grep -q "^${FORGEJO_RUNNER_CONTAINER}$"; then
         log_warn "Forgejo Runner is already installed."
+
         return
     fi