feat(helm): add environment variables for Reflex configuration

Changes:
- Add API_URL, FRONTEND_PORT, BACKEND_PORT env vars to deployment
- Construct DATABASE_URL from PostgreSQL connection params
- Construct REDIS_URL from Redis connection params (with/without password)
- Add reflex.apiUrl config to values files:
  * Default: http://localhost:8000
  * Staging: https://staging.peikarband.ir
  * Production: https://peikarband.ir
- Add ENVIRONMENT to configMap

This ensures rxconfig.py gets proper environment-specific configuration
without hardcoding values. The app now works correctly in all environments
(dev, staging, production) with appropriate URLs and settings.

helm/peikarband/values-staging.yaml

@@ -5,6 +5,10 @@ replicaCount: 1
 image:
   pullPolicy: Always
 
+# Reflex configuration for staging
+reflex:
+  apiUrl: "https://staging.peikarband.ir"  # Staging API URL
+
 resources:
   limits:
     cpu: 500m