Add environment configuration and local development documentation

- Parameterize CORS_ORIGINS in docker-compose.swarm.yml
- Add .env.example with configuration options
- Create comprehensive LOCAL_DEVELOPMENT.md guide
- Update README.md with environment variable documentation
- Provide alternatives for local development without production domain

🤖 Generated with [Claude Code](https://claude.ai/code)

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

backend/.env.production

@@ -0,0 +1,31 @@
+# Production Environment Configuration
+DATABASE_URL=postgresql://hive:hive@postgres:5432/hive
+REDIS_URL=redis://redis:6379/0
+
+# Application Settings
+LOG_LEVEL=info
+CORS_ORIGINS=https://hive.deepblack.cloud,http://hive.deepblack.cloud
+MAX_WORKERS=2
+
+# Database Pool Settings
+DB_POOL_SIZE=10
+DB_MAX_OVERFLOW=20
+DB_POOL_RECYCLE=3600
+
+# HTTP Client Settings
+HTTP_TIMEOUT=30
+HTTP_POOL_CONNECTIONS=100
+HTTP_POOL_MAXSIZE=100
+
+# Health Check Settings
+HEALTH_CHECK_TIMEOUT=10
+STARTUP_TIMEOUT=60
+
+# Security Settings
+SECRET_KEY=your-secret-key-here
+ALGORITHM=HS256
+ACCESS_TOKEN_EXPIRE_MINUTES=30
+
+# Monitoring
+PROMETHEUS_ENABLED=true
+METRICS_PORT=9090