Add setup-env.sh script for environment configuration

Creates interactive setup script that configures .env files for both
frontend and backend with the correct server IP address. Features:
- Auto-detects current server IP
- Prompts for custom IP if needed
- Checks for existing .env files before overwriting
- Configures REACT_APP_API_BASE, REACT_APP_API_HOST, and CORS settings

This prevents the issue where React apps start with localhost fallback
when .env files are missing or created after server startup.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/setup-env.sh

@@ -0,0 +1,88 @@
+#!/bin/bash
+# Setup script for CVE Dashboard environment configuration
+# Creates .env files from .env.example templates with proper IP configuration
+
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+PROJECT_ROOT="$(dirname "$SCRIPT_DIR")"
+
+echo "CVE Dashboard Environment Setup"
+echo "================================"
+echo ""
+
+# Detect current IP address
+DETECTED_IP=$(hostname -I | awk '{print $1}')
+
+# Prompt for IP address
+read -p "Enter server IP address [$DETECTED_IP]: " INPUT_IP
+SERVER_IP="${INPUT_IP:-$DETECTED_IP}"
+
+if [ -z "$SERVER_IP" ]; then
+    echo "ERROR: No IP address provided and auto-detection failed."
+    exit 1
+fi
+
+echo ""
+echo "Using IP: $SERVER_IP"
+echo ""
+
+# Setup backend .env
+BACKEND_ENV="$PROJECT_ROOT/backend/.env"
+if [ -f "$BACKEND_ENV" ]; then
+    read -p "backend/.env exists. Overwrite? [y/N]: " OVERWRITE
+    if [[ ! "$OVERWRITE" =~ ^[Yy]$ ]]; then
+        echo "Skipping backend/.env"
+    else
+        cat > "$BACKEND_ENV" << ENVFILE
+# Backend Configuration
+PORT=3001
+API_HOST=$SERVER_IP
+CORS_ORIGINS=http://$SERVER_IP:3000
+ENVFILE
+        echo "Created backend/.env"
+    fi
+else
+    cat > "$BACKEND_ENV" << ENVFILE
+# Backend Configuration
+PORT=3001
+API_HOST=$SERVER_IP
+CORS_ORIGINS=http://$SERVER_IP:3000
+ENVFILE
+    echo "Created backend/.env"
+fi
+
+# Setup frontend .env
+FRONTEND_ENV="$PROJECT_ROOT/frontend/.env"
+if [ -f "$FRONTEND_ENV" ]; then
+    read -p "frontend/.env exists. Overwrite? [y/N]: " OVERWRITE
+    if [[ ! "$OVERWRITE" =~ ^[Yy]$ ]]; then
+        echo "Skipping frontend/.env"
+    else
+        cat > "$FRONTEND_ENV" << ENVFILE
+# Frontend Configuration
+# API_BASE should include the /api path
+REACT_APP_API_BASE=http://$SERVER_IP:3001/api
+# API_HOST is used for direct file URLs (no /api)
+REACT_APP_API_HOST=http://$SERVER_IP:3001
+ENVFILE
+        echo "Created frontend/.env"
+    fi
+else
+    cat > "$FRONTEND_ENV" << ENVFILE
+# Frontend Configuration
+# API_BASE should include the /api path
+REACT_APP_API_BASE=http://$SERVER_IP:3001/api
+# API_HOST is used for direct file URLs (no /api)
+REACT_APP_API_HOST=http://$SERVER_IP:3001
+ENVFILE
+    echo "Created frontend/.env"
+fi
+
+echo ""
+echo "Setup complete!"
+echo ""
+echo "Next steps:"
+echo "  1. If servers are running, restart them to apply changes"
+echo "  2. Run: ./start-servers.sh"
+echo ""