Initial commit: 50 shell-script generators with web UI

- 8 categories / 50 generators covering middleware, databases, runtimes,
  systemd services, system tools, network, monitoring, security
- VNC supports XFCE / GNOME / KDE Plasma / MATE / LXQt desktops
- Node.js versions 18-26 (incl. current LTS 24 Krypton and current 26)
- Live preview, copy / download / multi-script bundle in web UI
- Distro-aware (Ubuntu/Debian/CentOS/RHEL/Rocky/Alma/Fedora)
- All 50 generators pass bash -n syntax check
- Zero pip dependencies (Flask stdlib only)

shell-gen.service

@@ -0,0 +1,15 @@
+[Unit]
+Description=shell-gen - Linux shell script generator
+After=network.target
+
+[Service]
+Type=simple
+User=root
+WorkingDirectory=/root/shell-gen
+ExecStart=/usr/bin/python3 /root/shell-gen/app.py
+Restart=on-failure
+RestartSec=3
+Environment=PORT=5099
+
+[Install]
+WantedBy=multi-user.target