CUB-126: Update Control Center deployment for Go + React

- Updated docker-compose.yml for Go + React + PostgreSQL
- Go backend multi-stage Dockerfile (already existed)
- React frontend multi-stage Dockerfile with nginx SPA config (already existed)
- Kiosk start script and systemd unit
- Deployment README
- .env.example for environment variables

kiosk/control-center-kiosk.service

@@ -0,0 +1,42 @@
+# Control Center Kiosk Service
+# =============================
+# Systemd unit file for auto-starting the Control Center kiosk on boot
+# 
+# Install: sudo cp control-center-kiosk.service /etc/systemd/system/
+# Enable:  sudo systemctl enable control-center-kiosk
+# Start:   sudo systemctl start control-center-kiosk
+# Status:  sudo systemctl status control-center-kiosk
+# Logs:    sudo journalctl -u control-center-kiosk -f
+
+[Unit]
+Description=Control Center Kiosk - Chrome Browser Dashboard
+Documentation=https://code.cubecraftcreations.com/CubeCraft-Creations/Control-Center
+After=graphical-session.target network-online.target
+Wants=network-online.target
+PartOf=graphical-session.target
+
+[Service]
+Type=simple
+ExecStart=/home/overseer/projects/Control-Center/kiosk/start-kiosk.sh http://localhost:3000
+ExecReload=/bin/kill -HUP $MAINPID
+Restart=on-failure
+RestartSec=5
+Environment=DISPLAY=:0
+Environment=XAUTHORITY=/home/overseer/.Xauthority
+WorkingDirectory=/home/overseer/projects/Control-Center
+User=overseer
+Group=overseer
+StandardOutput=journal
+StandardError=journal
+SyslogIdentifier=control-center-kiosk
+
+# Security hardening
+NoNewPrivileges=true
+ProtectSystem=strict
+ProtectHome=true
+PrivateTmp=true
+ReadWritePaths=/home/overseer/.config/chromium
+ReadWritePaths=/var/log/journal
+
+[Install]
+WantedBy=graphical-session.target

kiosk/start-kiosk.sh

@@ -0,0 +1,88 @@
+#!/bin/bash
+# Control Center Kiosk Startup Script
+# ====================================
+# This script launches Chromium in kiosk mode for the Control Center dashboard
+# Usage: ./start-kiosk.sh [frontend-url]
+
+set -e
+
+FRONTEND_URL="${1:-http://localhost:3000}"
+BROWSER_WINDOW="chromium-browser"
+
+# ── Functions ────────────────────────────────────────────────────────────
+
+log() {
+    echo "[$(date '+%Y-%m-%d %H:%M:%S')] $*"
+}
+
+cleanup() {
+    log "Stopping kiosk browser..."
+    pkill -f "chromium-browser.*--kiosk" || true
+}
+
+trap cleanup SIGINT SIGTERM
+
+# ── Check prerequisites ──────────────────────────────────────────────────
+
+check_browser() {
+    if ! command -v chromium-browser &> /dev/null; then
+        log "ERROR: chromium-browser not found"
+        log "Install with: sudo apt-get install chromium"
+        exit 1
+    fi
+}
+
+check_x_server() {
+    if [ -z "$DISPLAY" ]; then
+        log "ERROR: DISPLAY environment variable not set"
+        log "This script requires an X server session"
+        exit 1
+    fi
+}
+
+# ── Main ────────────────────────────────────────────────────────────────
+
+main() {
+    log "Starting Control Center Kiosk..."
+    log "Frontend URL: $FRONTEND_URL"
+    
+    check_browser
+    check_x_server
+    
+    # Clean up any existing browser instances
+    cleanup
+    
+    # Launch Chromium in kiosk mode
+    # --kiosk: Fullscreen without browser UI
+    # --incognito: Clean session
+    # --noerrdialogs: Suppress error dialogs
+    # --disable-notifications: Disable notifications
+    # --disable-extensions: Disable extensions
+    # --disable-plugins-discovery: Disable plugins
+    # --disable-sync: Disable sync
+    # --disable-web-security: Allow CORS (needed for local API calls)
+    # --ignore-certificate-errors: Ignore SSL errors (for local dev)
+    # --gpu: Enable GPU acceleration
+    # --start-fullscreen: Start in fullscreen mode
+    chromium-browser \
+        --kiosk \
+        --incognito \
+        --noerrdialogs \
+        --disable-notifications \
+        --disable-extensions \
+        --disable-plugins-discovery \
+        --disable-sync \
+        --disable-web-security \
+        --ignore-certificate-errors \
+        --gpu \
+        --start-fullscreen \
+        "$FRONTEND_URL" &
+    
+    KIOSK_PID=$!
+    log "Kiosk browser started (PID: $KIOSK_PID)"
+    
+    # Wait for browser to exit
+    wait $KIOSK_PID
+}
+
+main "$@"