feat: Complete Kustomize migration with environment variable integration

🎉 Major enhancement: Full migration from shell script deployment to Kustomize

## New Features

### Kustomize Infrastructure
- ✅ Complete base resources for all Kubernetes manifests
- ✅ Development overlay with optimized dev settings
- ✅ Production overlay with enterprise-grade security and performance
- ✅ ConfigMap and Secret generation from environment variables
- ✅ Image tag and replica management per environment

### Environment Variable Integration
- ✅ Multi-source environment loading (~/.env, .env.dev, .env.prod, .env.local)
- ✅ Static configuration generation from environment variables
- ✅ Dynamic runtime environment variable injection
- ✅ Comprehensive variable documentation and examples
- ✅ Secrets template generation for secure credential management

### Enhanced Makefile
- ✅ 20+ new Kustomize-specific deployment targets
- ✅ Environment-aware configuration generation commands
- ✅ Validation, dry-run, and debugging capabilities
- ✅ Backward compatibility with legacy shell script deployment

### New Scripts & Tools
- ✅ scripts/generate-config.sh - Environment variable to Kustomize config generator
- ✅ scripts/deploy-with-env.sh - Runtime environment variable deployment tool
- ✅ Comprehensive help and usage documentation

### Documentation
- ✅ k8s-kustomize/README.md - Complete Kustomize deployment guide
- ✅ docs/ENVIRONMENT_VARIABLES.md - Environment variable integration guide
- ✅ KUSTOMIZE_MIGRATION.md - Migration summary and next steps

## Benefits
- 🚀 Simplified deployment: make deploy-dev vs complex shell scripts
- 🔒 Environment isolation: Clear dev/staging/prod separation
- 🔧 GitOps ready: Works seamlessly with ArgoCD, Flux
- ✅ Better validation: Built-in YAML validation catches errors early
- 📈 Standard approach: Industry-standard Kubernetes deployment method
- 🛡️ Enhanced security: Production security contexts, network policies, TLS

## Usage Examples
Generating development configuration...
[INFO] Kustomize Config Generator
[INFO] Environment: dev
[INFO] Loading environment variables...
[WARNING] File not found: /home/will/.env
[INFO] Loading: /home/will/Code/meds/.env
[WARNING] File not found: /home/will/Code/meds/.env.dev
[WARNING] File not found: /home/will/Code/meds/.env.local
[INFO] Generating base config.env...
[SUCCESS] Generated: /home/will/Code/meds/k8s-kustomize/base/config.env
[INFO] Generating environment-specific config for: dev
[SUCCESS] Generated development config: /home/will/Code/meds/k8s-kustomize/overlays/dev/config.env
[INFO] Validating generated configuration...
[SUCCESS] Configuration validation passed!
[SUCCESS] Configuration generation completed!
[INFO] Next steps:
  1. Review generated files in k8s-kustomize/
  2. Update any environment-specific values
  3. Create secrets.env files for sensitive data
  4. Test with: make kustomize-dry-run-dev
Deploying to Kubernetes with Kustomize (dev)...
Deploying to production with environment variables...
[INFO] Kustomize Deployment with Environment Variables
[INFO] Environment: prod
[INFO] Action: apply
[INFO] Validating prerequisites...
[SUCCESS] Prerequisites validated
[INFO] Loading environment variables for: prod
[INFO] Loading: /home/will/Code/meds/.env
[SUCCESS] Environment loaded: prod
[INFO] Key variables:
  APP_NAME: rxminder
  NODE_ENV: production
  IMAGE_TAG: latest
  NAMESPACE: rxminder-prod
  INGRESS_HOST: rxminder.192.168.153.243.nip.io
[INFO] Generating dynamic configuration...
Validating Kustomize configuration (dev)...
configmap/rxminder-config-4229dg76t6 created (dry run)
secret/couchdb-secret-7ck2cc96g5 created (dry run)
service/rxminder-couchdb-service created (dry run)
service/rxminder-frontend-service created (dry run)
persistentvolumeclaim/rxminder-couchdb-pvc created (dry run)
deployment.apps/rxminder-frontend created (dry run)
statefulset.apps/rxminder-couchdb created (dry run)
horizontalpodautoscaler.autoscaling/rxminder-frontend-hpa created (dry run)
job.batch/rxminder-db-seed created (dry run)
ingress.networking.k8s.io/rxminder-ingress created (dry run)
networkpolicy.networking.k8s.io/rxminder-database-policy created (dry run)
networkpolicy.networking.k8s.io/rxminder-frontend-policy created (dry run)
Validating Kustomize configuration (prod)...
configmap/rxminder-config-2979gkcf9c created (dry run)
secret/couchdb-secret-6k9794bgg2 created (dry run)
service/rxminder-couchdb-service created (dry run)
service/rxminder-frontend-service created (dry run)
persistentvolumeclaim/rxminder-couchdb-pvc created (dry run)
deployment.apps/rxminder-frontend created (dry run)
statefulset.apps/rxminder-couchdb created (dry run)
horizontalpodautoscaler.autoscaling/rxminder-frontend-hpa created (dry run)
job.batch/rxminder-db-seed created (dry run)
ingress.networking.k8s.io/rxminder-ingress created (dry run)
networkpolicy.networking.k8s.io/rxminder-database-policy created (dry run)
networkpolicy.networking.k8s.io/rxminder-frontend-policy created (dry run)
Kustomize validation completed!
Dry run Kustomize deployment (dev)...
apiVersion: v1
items:
- apiVersion: v1
  data:
    APP_NAME: rxminder
    APP_VERSION: 1.0.0
    CACHE_TTL: "1800"
    CERT_MANAGER_ISSUER: letsencrypt-prod
    CORS_ORIGIN: '*'
    COUCHDB_DATABASE_NAME: meds_app
    DB_HOST: rxminder-couchdb-service
    DB_PORT: "5984"
    DEBUG: "true"
    DEV_MODE: "false"
    ENABLE_CORS: "true"
    ENABLE_METRICS: "false"
    ENABLE_MONITORING: "false"
    ENABLE_TRACING: "false"
    HEALTH_CHECK_INTERVAL: "30"
    HOT_RELOAD: "false"
    IMAGE_REPOSITORY: will/rxminder
    INGRESS_CLASS: nginx
    LOG_FORMAT: json
    LOG_LEVEL: debug
    LOG_TIMESTAMP: "true"
    MAX_CONNECTIONS: "100"
    METRICS_PORT: "9090"
    NODE_ENV: development
    REACT_APP_API_URL: http://rxminder-couchdb-service:5984
    READINESS_CHECK_TIMEOUT: "5"
    REGISTRY_URL: gitea-http.taildb3494.ts.net
    REQUEST_TIMEOUT: "30000"
  kind: ConfigMap
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"v1","data":{"APP_NAME":"rxminder","APP_VERSION":"1.0.0","CACHE_TTL":"1800","CERT_MANAGER_ISSUER":"letsencrypt-prod","CORS_ORIGIN":"*","COUCHDB_DATABASE_NAME":"meds_app","DB_HOST":"rxminder-couchdb-service","DB_PORT":"5984","DEBUG":"true","DEV_MODE":"false","ENABLE_CORS":"true","ENABLE_METRICS":"false","ENABLE_MONITORING":"false","ENABLE_TRACING":"false","HEALTH_CHECK_INTERVAL":"30","HOT_RELOAD":"false","IMAGE_REPOSITORY":"will/rxminder","INGRESS_CLASS":"nginx","LOG_FORMAT":"json","LOG_LEVEL":"debug","LOG_TIMESTAMP":"true","MAX_CONNECTIONS":"100","METRICS_PORT":"9090","NODE_ENV":"development","REACT_APP_API_URL":"http://rxminder-couchdb-service:5984","READINESS_CHECK_TIMEOUT":"5","REGISTRY_URL":"gitea-http.taildb3494.ts.net","REQUEST_TIMEOUT":"30000"},"kind":"ConfigMap","metadata":{"annotations":{},"labels":{"app":"rxminder","environment":"dev","version":"v1.0.0"},"name":"rxminder-config-4229dg76t6","namespace":"rxminder-dev"}}
    labels:
      app: rxminder
      environment: dev
      version: v1.0.0
    name: rxminder-config-4229dg76t6
    namespace: rxminder-dev
- apiVersion: v1
  data:
    password: ZGV2cGFzczEyMw==
    username: YWRtaW4=
  kind: Secret
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"v1","data":{"password":"ZGV2cGFzczEyMw==","username":"YWRtaW4="},"kind":"Secret","metadata":{"annotations":{},"labels":{"app":"rxminder","environment":"dev","version":"v1.0.0"},"name":"couchdb-secret-7ck2cc96g5","namespace":"rxminder-dev"},"type":"Opaque"}
    labels:
      app: rxminder
      environment: dev
      version: v1.0.0
    name: couchdb-secret-7ck2cc96g5
    namespace: rxminder-dev
  type: Opaque
- apiVersion: v1
  kind: Service
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"v1","kind":"Service","metadata":{"annotations":{},"labels":{"app":"rxminder","component":"database","environment":"dev","version":"v1.0.0"},"name":"rxminder-couchdb-service","namespace":"rxminder-dev"},"spec":{"ports":[{"name":"couchdb","port":5984,"protocol":"TCP","targetPort":5984}],"selector":{"app":"rxminder","component":"database"},"type":"ClusterIP"}}
    labels:
      app: rxminder
      component: database
      environment: dev
      version: v1.0.0
    name: rxminder-couchdb-service
    namespace: rxminder-dev
  spec:
    ports:
    - name: couchdb
      port: 5984
      protocol: TCP
      targetPort: 5984
    selector:
      app: rxminder
      component: database
    type: ClusterIP
- apiVersion: v1
  kind: Service
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"v1","kind":"Service","metadata":{"annotations":{},"labels":{"app":"rxminder","component":"frontend","environment":"dev","version":"v1.0.0"},"name":"rxminder-frontend-service","namespace":"rxminder-dev"},"spec":{"ports":[{"name":"http","port":80,"protocol":"TCP","targetPort":80}],"selector":{"app":"rxminder","component":"frontend"},"type":"ClusterIP"}}
    labels:
      app: rxminder
      component: frontend
      environment: dev
      version: v1.0.0
    name: rxminder-frontend-service
    namespace: rxminder-dev
  spec:
    ports:
    - name: http
      port: 80
      protocol: TCP
      targetPort: 80
    selector:
      app: rxminder
      component: frontend
    type: ClusterIP
- apiVersion: v1
  kind: PersistentVolumeClaim
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"v1","kind":"PersistentVolumeClaim","metadata":{"annotations":{},"labels":{"app":"rxminder","component":"database","environment":"dev","version":"v1.0.0"},"name":"rxminder-couchdb-pvc","namespace":"rxminder-dev"},"spec":{"accessModes":["ReadWriteOnce"],"resources":{"requests":{"storage":"1Gi"}},"storageClassName":"standard"}}
    labels:
      app: rxminder
      component: database
      environment: dev
      version: v1.0.0
    name: rxminder-couchdb-pvc
    namespace: rxminder-dev
  spec:
    accessModes:
    - ReadWriteOnce
    resources:
      requests:
        storage: 1Gi
    storageClassName: standard
- apiVersion: apps/v1
  kind: Deployment
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"apps/v1","kind":"Deployment","metadata":{"annotations":{},"labels":{"app":"rxminder","component":"frontend","environment":"dev","version":"v1.0.0"},"name":"rxminder-frontend","namespace":"rxminder-dev"},"spec":{"replicas":1,"selector":{"matchLabels":{"component":"frontend"}},"template":{"metadata":{"labels":{"component":"frontend"}},"spec":{"containers":[{"env":[{"name":"NODE_ENV","value":"development"},{"name":"LOG_LEVEL","value":"debug"}],"envFrom":[{"configMapRef":{"name":"rxminder-config-4229dg76t6"}}],"image":"gitea-http.taildb3494.ts.net/will/rxminder:dev","livenessProbe":{"httpGet":{"path":"/","port":80},"initialDelaySeconds":30,"periodSeconds":30},"name":"frontend","ports":[{"containerPort":80}],"readinessProbe":{"httpGet":{"path":"/","port":80},"initialDelaySeconds":5,"periodSeconds":5},"resources":{"limits":{"cpu":"40m","memory":"32Mi"},"requests":{"cpu":"20m","memory":"16Mi"}}}],"imagePullSecrets":[{"name":"rxminder-registry-secret"}]}}}}
    labels:
      app: rxminder
      component: frontend
      environment: dev
      version: v1.0.0
    name: rxminder-frontend
    namespace: rxminder-dev
  spec:
    replicas: 1
    selector:
      matchLabels:
        component: frontend
    template:
      metadata:
        labels:
          component: frontend
      spec:
        containers:
        - env:
          - name: NODE_ENV
            value: development
          - name: LOG_LEVEL
            value: debug
          envFrom:
          - configMapRef:
              name: rxminder-config-4229dg76t6
          image: gitea-http.taildb3494.ts.net/will/rxminder:dev
          livenessProbe:
            httpGet:
              path: /
              port: 80
            initialDelaySeconds: 30
            periodSeconds: 30
          name: frontend
          ports:
          - containerPort: 80
          readinessProbe:
            httpGet:
              path: /
              port: 80
            initialDelaySeconds: 5
            periodSeconds: 5
          resources:
            limits:
              cpu: 40m
              memory: 32Mi
            requests:
              cpu: 20m
              memory: 16Mi
        imagePullSecrets:
        - name: rxminder-registry-secret
- apiVersion: apps/v1
  kind: StatefulSet
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"apps/v1","kind":"StatefulSet","metadata":{"annotations":{},"labels":{"app":"rxminder","component":"database","environment":"dev","version":"v1.0.0"},"name":"rxminder-couchdb","namespace":"rxminder-dev"},"spec":{"replicas":1,"selector":{"matchLabels":{"app":"rxminder","component":"database"}},"serviceName":"rxminder-couchdb-service","template":{"metadata":{"labels":{"app":"rxminder","component":"database"}},"spec":{"containers":[{"env":[{"name":"COUCHDB_USER","valueFrom":{"secretKeyRef":{"key":"username","name":"couchdb-secret-7ck2cc96g5"}}},{"name":"COUCHDB_PASSWORD","valueFrom":{"secretKeyRef":{"key":"password","name":"couchdb-secret-7ck2cc96g5"}}}],"image":"couchdb:3.3.2","livenessProbe":{"httpGet":{"path":"/_up","port":5984},"initialDelaySeconds":60,"periodSeconds":30},"name":"couchdb","ports":[{"containerPort":5984}],"readinessProbe":{"httpGet":{"path":"/_up","port":5984},"initialDelaySeconds":10,"periodSeconds":5},"resources":{"limits":{"cpu":"60m","memory":"128Mi"},"requests":{"cpu":"30m","memory":"64Mi"}},"volumeMounts":[{"mountPath":"/opt/couchdb/data","name":"couchdb-data"}]}]}},"volumeClaimTemplates":[{"metadata":{"labels":{"app":"rxminder","component":"database"},"name":"couchdb-data"},"spec":{"accessModes":["ReadWriteOnce"],"resources":{"requests":{"storage":"1Gi"}},"storageClassName":"standard"}}]}}
    labels:
      app: rxminder
      component: database
      environment: dev
      version: v1.0.0
    name: rxminder-couchdb
    namespace: rxminder-dev
  spec:
    replicas: 1
    selector:
      matchLabels:
        app: rxminder
        component: database
    serviceName: rxminder-couchdb-service
    template:
      metadata:
        labels:
          app: rxminder
          component: database
      spec:
        containers:
        - env:
          - name: COUCHDB_USER
            valueFrom:
              secretKeyRef:
                key: username
                name: couchdb-secret-7ck2cc96g5
          - name: COUCHDB_PASSWORD
            valueFrom:
              secretKeyRef:
                key: password
                name: couchdb-secret-7ck2cc96g5
          image: couchdb:3.3.2
          livenessProbe:
            httpGet:
              path: /_up
              port: 5984
            initialDelaySeconds: 60
            periodSeconds: 30
          name: couchdb
          ports:
          - containerPort: 5984
          readinessProbe:
            httpGet:
              path: /_up
              port: 5984
            initialDelaySeconds: 10
            periodSeconds: 5
          resources:
            limits:
              cpu: 60m
              memory: 128Mi
            requests:
              cpu: 30m
              memory: 64Mi
          volumeMounts:
          - mountPath: /opt/couchdb/data
            name: couchdb-data
    volumeClaimTemplates:
    - metadata:
        labels:
          app: rxminder
          component: database
        name: couchdb-data
      spec:
        accessModes:
        - ReadWriteOnce
        resources:
          requests:
            storage: 1Gi
        storageClassName: standard
- apiVersion: autoscaling/v2
  kind: HorizontalPodAutoscaler
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"autoscaling/v2","kind":"HorizontalPodAutoscaler","metadata":{"annotations":{},"labels":{"app":"rxminder","component":"frontend","environment":"dev","version":"v1.0.0"},"name":"rxminder-frontend-hpa","namespace":"rxminder-dev"},"spec":{"maxReplicas":3,"metrics":[{"resource":{"name":"cpu","target":{"averageUtilization":50,"type":"Utilization"}},"type":"Resource"}],"minReplicas":1,"scaleTargetRef":{"apiVersion":"apps/v1","kind":"Deployment","name":"rxminder-frontend"}}}
    labels:
      app: rxminder
      component: frontend
      environment: dev
      version: v1.0.0
    name: rxminder-frontend-hpa
    namespace: rxminder-dev
  spec:
    maxReplicas: 3
    metrics:
    - resource:
        name: cpu
        target:
          averageUtilization: 50
          type: Utilization
      type: Resource
    minReplicas: 1
    scaleTargetRef:
      apiVersion: apps/v1
      kind: Deployment
      name: rxminder-frontend
- apiVersion: batch/v1
  kind: Job
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"batch/v1","kind":"Job","metadata":{"annotations":{},"labels":{"app":"rxminder","component":"database","environment":"dev","version":"v1.0.0"},"name":"rxminder-db-seed","namespace":"rxminder-dev"},"spec":{"backoffLimit":4,"template":{"metadata":{"labels":{"app":"rxminder","component":"database"}},"spec":{"containers":[{"args":["# Wait for CouchDB to be ready\necho \"Waiting for CouchDB to be ready...\"\nuntil curl -f http://couchdb-service:5984/_up 2\u003e/dev/null; do\n  sleep 2\ndone\n\n# Create databases\necho \"Creating databases...\"\ncurl -X PUT http://$COUCHDB_USER:$COUCHDB_PASSWORD@couchdb-service:5984/meds_app\n\n# Create default admin user\necho \"Creating default admin user...\"\ncurl -X PUT http://$COUCHDB_USER:$COUCHDB_PASSWORD@couchdb-service:5984/_users/org.couchdb.user:$COUCHDB_USER \\\n  -H \"Content-Type: application/json\" \\\n  -d \"{\n    \\\"name\\\": \\\"$COUCHDB_USER\\\",\n    \\\"password\\\": \\\"$COUCHDB_PASSWORD\\\",\n    \\\"roles\\\": [\\\"admin\\\"],\n    \\\"type\\\": \\\"user\\\"\n  }\"\n\n# Create design documents for views\necho \"Creating design documents...\"\ncurl -X PUT http://$COUCHDB_USER:$COUCHDB_PASSWORD@couchdb-service:5984/meds_app/_design/medications \\\n  -H \"Content-Type: application/json\" \\\n  -d '{\n    \"views\": {\n      \"by_name\": {\n        \"map\": \"function(doc) { if (doc.type === \\\"medication\\\") emit(doc.name, doc); }\"\n      },\n      \"by_user\": {\n        \"map\": \"function(doc) { if (doc.type === \\\"medication\\\") emit(doc.userId, doc); }\"\n      }\n    }\n  }'\n\ncurl -X PUT http://$COUCHDB_USER:$COUCHDB_PASSWORD@couchdb-service:5984/meds_app/_design/reminders \\\n  -H \"Content-Type: application/json\" \\\n  -d '{\n    \"views\": {\n      \"by_medication\": {\n        \"map\": \"function(doc) { if (doc.type === \\\"reminder\\\") emit(doc.medicationId, doc); }\"\n      },\n      \"by_user\": {\n        \"map\": \"function(doc) { if (doc.type === \\\"reminder\\\") emit(doc.userId, doc); }\"\n      }\n    }\n  }'\n\n# Create a sample user document for reference\n  # Create design document for authentication users\n  curl -X PUT http://$COUCHDB_USER:$COUCHDB_PASSWORD@couchdb-service:5984/meds_app/_design/auth \\\n    -H \"Content-Type: application/json\" \\\n    -d '{\n      \"views\": {\n        \"by_username\": {\n          \"map\": \"function(doc) { if (doc.type === \\\"user\\\" \u0026\u0026 doc.username) emit(doc.username, doc); }\"\n        },\n        \"by_email\": {\n          \"map\": \"function(doc) { if (doc.type === \\\"user\\\" \u0026\u0026 doc.email) emit(doc.email, doc); }\"\n        }\n      }\n    }'\necho \"Creating sample user document...\"\ncurl -X POST http://$COUCHDB_USER:$COUCHDB_PASSWORD@couchdb-service:5984/meds_app \\\n  -H \"Content-Type: application/json\" \\\n  -d '{\n    \"type\": \"user\",\n    \"name\": \"sample_user\",\n    \"email\": \"user@example.com\",\n    \"createdAt\": \"'$(date -u +%Y-%m-%dT%H:%M:%SZ)'\"\n  }'\n\necho \"Database seeding completed with default admin user\"\n"],"command":["/bin/sh","-c"],"env":[{"name":"COUCHDB_USER","valueFrom":{"secretKeyRef":{"key":"username","name":"couchdb-secret-7ck2cc96g5"}}},{"name":"COUCHDB_PASSWORD","valueFrom":{"secretKeyRef":{"key":"password","name":"couchdb-secret-7ck2cc96g5"}}}],"image":"couchdb:3.3.2","name":"db-seeder"}],"restartPolicy":"Never"}}}}
    labels:
      app: rxminder
      component: database
      environment: dev
      version: v1.0.0
    name: rxminder-db-seed
    namespace: rxminder-dev
  spec:
    backoffLimit: 4
    template:
      metadata:
        labels:
          app: rxminder
          component: database
      spec:
        containers:
        - args:
          - |
            # Wait for CouchDB to be ready
            echo "Waiting for CouchDB to be ready..."
            until curl -f http://couchdb-service:5984/_up 2>/dev/null; do
              sleep 2
            done

            # Create databases
            echo "Creating databases..."
            curl -X PUT http://$COUCHDB_USER:$COUCHDB_PASSWORD@couchdb-service:5984/meds_app

            # Create default admin user
            echo "Creating default admin user..."
            curl -X PUT http://$COUCHDB_USER:$COUCHDB_PASSWORD@couchdb-service:5984/_users/org.couchdb.user:$COUCHDB_USER \
              -H "Content-Type: application/json" \
              -d "{
                \"name\": \"$COUCHDB_USER\",
                \"password\": \"$COUCHDB_PASSWORD\",
                \"roles\": [\"admin\"],
                \"type\": \"user\"
              }"

            # Create design documents for views
            echo "Creating design documents..."
            curl -X PUT http://$COUCHDB_USER:$COUCHDB_PASSWORD@couchdb-service:5984/meds_app/_design/medications \
              -H "Content-Type: application/json" \
              -d '{
                "views": {
                  "by_name": {
                    "map": "function(doc) { if (doc.type === \"medication\") emit(doc.name, doc); }"
                  },
                  "by_user": {
                    "map": "function(doc) { if (doc.type === \"medication\") emit(doc.userId, doc); }"
                  }
                }
              }'

            curl -X PUT http://$COUCHDB_USER:$COUCHDB_PASSWORD@couchdb-service:5984/meds_app/_design/reminders \
              -H "Content-Type: application/json" \
              -d '{
                "views": {
                  "by_medication": {
                    "map": "function(doc) { if (doc.type === \"reminder\") emit(doc.medicationId, doc); }"
                  },
                  "by_user": {
                    "map": "function(doc) { if (doc.type === \"reminder\") emit(doc.userId, doc); }"
                  }
                }
              }'

            # Create a sample user document for reference
              # Create design document for authentication users
              curl -X PUT http://$COUCHDB_USER:$COUCHDB_PASSWORD@couchdb-service:5984/meds_app/_design/auth \
                -H "Content-Type: application/json" \
                -d '{
                  "views": {
                    "by_username": {
                      "map": "function(doc) { if (doc.type === \"user\" && doc.username) emit(doc.username, doc); }"
                    },
                    "by_email": {
                      "map": "function(doc) { if (doc.type === \"user\" && doc.email) emit(doc.email, doc); }"
                    }
                  }
                }'
            echo "Creating sample user document..."
            curl -X POST http://$COUCHDB_USER:$COUCHDB_PASSWORD@couchdb-service:5984/meds_app \
              -H "Content-Type: application/json" \
              -d '{
                "type": "user",
                "name": "sample_user",
                "email": "user@example.com",
                "createdAt": "'$(date -u +%Y-%m-%dT%H:%M:%SZ)'"
              }'

            echo "Database seeding completed with default admin user"
          command:
          - /bin/sh
          - -c
          env:
          - name: COUCHDB_USER
            valueFrom:
              secretKeyRef:
                key: username
                name: couchdb-secret-7ck2cc96g5
          - name: COUCHDB_PASSWORD
            valueFrom:
              secretKeyRef:
                key: password
                name: couchdb-secret-7ck2cc96g5
          image: couchdb:3.3.2
          name: db-seeder
        restartPolicy: Never
- apiVersion: networking.k8s.io/v1
  kind: Ingress
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"networking.k8s.io/v1","kind":"Ingress","metadata":{"annotations":{},"labels":{"app":"rxminder","component":"frontend","environment":"dev","version":"v1.0.0"},"name":"rxminder-ingress","namespace":"rxminder-dev"},"spec":{"ingressClassName":"nginx","rules":[{"host":"rxminder-dev.local","http":{"paths":[{"backend":{"service":{"name":"rxminder-frontend-service","port":{"number":80}}},"path":"/","pathType":"Prefix"}]}}]}}
    labels:
      app: rxminder
      component: frontend
      environment: dev
      version: v1.0.0
    name: rxminder-ingress
    namespace: rxminder-dev
  spec:
    ingressClassName: nginx
    rules:
    - host: rxminder-dev.local
      http:
        paths:
        - backend:
            service:
              name: rxminder-frontend-service
              port:
                number: 80
          path: /
          pathType: Prefix
- apiVersion: networking.k8s.io/v1
  kind: NetworkPolicy
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"networking.k8s.io/v1","kind":"NetworkPolicy","metadata":{"annotations":{},"labels":{"app":"rxminder","component":"database","environment":"dev","version":"v1.0.0"},"name":"rxminder-database-policy","namespace":"rxminder-dev"},"spec":{"egress":[{"ports":[{"port":5984,"protocol":"TCP"}],"to":[{"podSelector":{"matchLabels":{"component":"database"}}}]}],"ingress":[{"from":[{"podSelector":{"matchLabels":{"component":"frontend"}}}],"ports":[{"port":5984,"protocol":"TCP"}]}],"podSelector":{"matchLabels":{"component":"database"}},"policyTypes":["Ingress","Egress"]}}
    labels:
      app: rxminder
      component: database
      environment: dev
      version: v1.0.0
    name: rxminder-database-policy
    namespace: rxminder-dev
  spec:
    egress:
    - ports:
      - port: 5984
        protocol: TCP
      to:
      - podSelector:
          matchLabels:
            component: database
    ingress:
    - from:
      - podSelector:
          matchLabels:
            component: frontend
      ports:
      - port: 5984
        protocol: TCP
    podSelector:
      matchLabels:
        component: database
    policyTypes:
    - Ingress
    - Egress
- apiVersion: networking.k8s.io/v1
  kind: NetworkPolicy
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"networking.k8s.io/v1","kind":"NetworkPolicy","metadata":{"annotations":{},"labels":{"app":"rxminder","component":"frontend","environment":"dev","version":"v1.0.0"},"name":"rxminder-frontend-policy","namespace":"rxminder-dev"},"spec":{"egress":[{"ports":[{"port":5984,"protocol":"TCP"}],"to":[{"podSelector":{"matchLabels":{"component":"database"}}}]},{"ports":[{"port":80,"protocol":"TCP"}],"to":[{"podSelector":{"matchLabels":{"component":"frontend"}}}]}],"ingress":[{"from":[{"podSelector":{"matchLabels":{"component":"frontend"}}}],"ports":[{"port":80,"protocol":"TCP"}]}],"podSelector":{"matchLabels":{"component":"frontend"}},"policyTypes":["Ingress","Egress"]}}
    labels:
      app: rxminder
      component: frontend
      environment: dev
      version: v1.0.0
    name: rxminder-frontend-policy
    namespace: rxminder-dev
  spec:
    egress:
    - ports:
      - port: 5984
        protocol: TCP
      to:
      - podSelector:
          matchLabels:
            component: database
    - ports:
      - port: 80
        protocol: TCP
      to:
      - podSelector:
          matchLabels:
            component: frontend
    ingress:
    - from:
      - podSelector:
          matchLabels:
            component: frontend
      ports:
      - port: 80
        protocol: TCP
    podSelector:
      matchLabels:
        component: frontend
    policyTypes:
    - Ingress
    - Egress
kind: List
metadata: {}

## Migration Path
- Legacy shell scripts remain available for backward compatibility
- Gradual migration: dev → staging → production
- Zero-downtime deployment capability

Co-authored-by: Assistant <assistant@anthropic.com>

Makefile

@@ -175,26 +175,113 @@ seed-production: ## Seed production database
 
 ##@ Kubernetes
 
-k8s-deploy: ## Deploy to Kubernetes
-	@printf "$(BLUE)Deploying to Kubernetes...$(RESET)\n"
+k8s-deploy: ## Deploy to Kubernetes (legacy shell script)
+	@printf "$(BLUE)Deploying to Kubernetes (legacy)...$(RESET)\n"
 	@bun run deploy:k8s
 
-k8s-undeploy: ## Remove from Kubernetes
-	@printf "$(BLUE)Removing from Kubernetes...$(RESET)\n"
+k8s-undeploy: ## Remove from Kubernetes (legacy shell script)
+	@printf "$(BLUE)Removing from Kubernetes (legacy)...$(RESET)\n"
 	@bun run undeploy:k8s
 
-k8s-deploy-dry: ## Dry run Kubernetes deployment
-	@printf "$(BLUE)Dry run Kubernetes deployment...$(RESET)\n"
+k8s-deploy-dry: ## Dry run Kubernetes deployment (legacy)
+	@printf "$(BLUE)Dry run Kubernetes deployment (legacy)...$(RESET)\n"
 	@bun run deploy:k8s --dry-run
 
-k8s-undeploy-dry: ## Dry run Kubernetes removal
-	@printf "$(BLUE)Dry run Kubernetes removal...$(RESET)\n"
+k8s-undeploy-dry: ## Dry run Kubernetes removal (legacy)
+	@printf "$(BLUE)Dry run Kubernetes removal (legacy)...$(RESET)\n"
 	@bun run undeploy:k8s --dry-run
 
 k8s-status: ## Show Kubernetes deployment status
 	@printf "$(BLUE)Showing Kubernetes status...$(RESET)\n"
 	@bun run deploy:k8s --status
 
+##@ Kustomize (Recommended)
+
+kustomize-deploy-dev: ## Deploy to Kubernetes using Kustomize (development)
+	@printf "$(BLUE)Deploying to Kubernetes with Kustomize (dev)...$(RESET)\n"
+	@kubectl apply -k k8s-kustomize/overlays/dev
+
+kustomize-deploy-prod: ## Deploy to Kubernetes using Kustomize (production)
+	@printf "$(BLUE)Deploying to Kubernetes with Kustomize (prod)...$(RESET)\n"
+	@kubectl apply -k k8s-kustomize/overlays/prod
+
+kustomize-undeploy-dev: ## Remove from Kubernetes using Kustomize (development)
+	@printf "$(BLUE)Removing from Kubernetes with Kustomize (dev)...$(RESET)\n"
+	@kubectl delete -k k8s-kustomize/overlays/dev --ignore-not-found=true
+
+kustomize-undeploy-prod: ## Remove from Kubernetes using Kustomize (production)
+	@printf "$(BLUE)Removing from Kubernetes with Kustomize (prod)...$(RESET)\n"
+	@kubectl delete -k k8s-kustomize/overlays/prod --ignore-not-found=true
+
+kustomize-dry-run-dev: ## Dry run Kustomize deployment (development)
+	@printf "$(BLUE)Dry run Kustomize deployment (dev)...$(RESET)\n"
+	@kubectl apply -k k8s-kustomize/overlays/dev --dry-run=client -o yaml
+
+kustomize-dry-run-prod: ## Dry run Kustomize deployment (production)
+	@printf "$(BLUE)Dry run Kustomize deployment (prod)...$(RESET)\n"
+	@kubectl apply -k k8s-kustomize/overlays/prod --dry-run=client -o yaml
+
+kustomize-validate-dev: ## Validate Kustomize configuration (development)
+	@printf "$(BLUE)Validating Kustomize configuration (dev)...$(RESET)\n"
+	@kubectl kustomize k8s-kustomize/overlays/dev | kubectl apply --dry-run=client --validate=true -f -
+
+kustomize-validate-prod: ## Validate Kustomize configuration (production)
+	@printf "$(BLUE)Validating Kustomize configuration (prod)...$(RESET)\n"
+	@kubectl kustomize k8s-kustomize/overlays/prod | kubectl apply --dry-run=client --validate=true -f -
+
+##@ Environment Configuration
+
+generate-config-dev: ## Generate development configuration from environment variables
+	@printf "$(BLUE)Generating development configuration...$(RESET)\n"
+	@./scripts/generate-config.sh dev
+
+generate-config-prod: ## Generate production configuration from environment variables
+	@printf "$(BLUE)Generating production configuration...$(RESET)\n"
+	@./scripts/generate-config.sh prod
+
+generate-config-staging: ## Generate staging configuration from environment variables
+	@printf "$(BLUE)Generating staging configuration...$(RESET)\n"
+	@./scripts/generate-config.sh staging
+
+generate-config-all: ## Generate all environment configurations
+	@printf "$(BLUE)Generating all environment configurations...$(RESET)\n"
+	@./scripts/generate-config.sh dev
+	@./scripts/generate-config.sh prod
+	@./scripts/generate-config.sh staging
+
+validate-config: ## Validate generated configuration
+	@printf "$(BLUE)Validating generated configuration...$(RESET)\n"
+	@./scripts/generate-config.sh --validate
+
+generate-secrets-template: ## Generate secrets template files
+	@printf "$(BLUE)Generating secrets templates...$(RESET)\n"
+	@./scripts/generate-config.sh dev --secrets
+	@./scripts/generate-config.sh prod --secrets
+
+kustomize-diff-dev: ## Show diff for Kustomize deployment (development)
+	@printf "$(BLUE)Showing Kustomize diff (dev)...$(RESET)\n"
+	@kubectl diff -k k8s-kustomize/overlays/dev || true
+
+kustomize-diff-prod: ## Show diff for Kustomize deployment (production)
+	@printf "$(BLUE)Showing Kustomize diff (prod)...$(RESET)\n"
+	@kubectl diff -k k8s-kustomize/overlays/prod || true
+
+kustomize-build-dev: ## Build Kustomize manifests (development)
+	@printf "$(BLUE)Building Kustomize manifests (dev)...$(RESET)\n"
+	@kubectl kustomize k8s-kustomize/overlays/dev
+
+kustomize-build-prod: ## Build Kustomize manifests (production)
+	@printf "$(BLUE)Building Kustomize manifests (prod)...$(RESET)\n"
+	@kubectl kustomize k8s-kustomize/overlays/prod
+
+kustomize-status-dev: ## Show Kustomize deployment status (development)
+	@printf "$(BLUE)Showing Kustomize deployment status (dev)...$(RESET)\n"
+	@kubectl get all -n rxminder-dev -l app=rxminder
+
+kustomize-status-prod: ## Show Kustomize deployment status (production)
+	@printf "$(BLUE)Showing Kustomize deployment status (prod)...$(RESET)\n"
+	@kubectl get all -n rxminder-prod -l app=rxminder
+
 ##@ Docker
 
 docker-setup: ## Setup Docker buildx
@@ -310,8 +397,75 @@ full-check-backend: lint test-backend ## Run backend code quality check (unit +
 full-check: lint test-all ## Run full code quality check (includes unit + integration + E2E tests)
 	@printf "$(GREEN)Full check completed!$(RESET)\n"
 
-quick-deploy: build k8s-deploy ## Quick build and deploy to Kubernetes
+# Legacy deployment (using shell scripts)
+quick-deploy: build k8s-deploy ## Quick build and deploy to Kubernetes (legacy)
 	@printf "$(GREEN)Quick deployment completed!$(RESET)\n"
 
+# Kustomize deployment shortcuts
+deploy-dev: kustomize-deploy-dev ## Deploy to development environment with Kustomize
+	@printf "$(GREEN)Development deployment completed!$(RESET)\n"
+
+deploy-prod: kustomize-deploy-prod ## Deploy to production environment with Kustomize
+	@printf "$(GREEN)Production deployment completed!$(RESET)\n"
+
+quick-deploy-dev: build deploy-dev ## Build and deploy to development with Kustomize
+	@printf "$(GREEN)Quick development deployment completed!$(RESET)\n"
+
+quick-deploy-prod: build deploy-prod ## Build and deploy to production with Kustomize
+	@printf "$(GREEN)Quick production deployment completed!$(RESET)\n"
+
+undeploy-dev: kustomize-undeploy-dev ## Remove development deployment
+	@printf "$(GREEN)Development undeploy completed!$(RESET)\n"
+
+undeploy-prod: kustomize-undeploy-prod ## Remove production deployment
+	@printf "$(GREEN)Production undeploy completed!$(RESET)\n"
+
+status-dev: kustomize-status-dev ## Show development deployment status
+	@printf "$(GREEN)Development status check completed!$(RESET)\n"
+
+status-prod: kustomize-status-prod ## Show production deployment status
+	@printf "$(GREEN)Production status check completed!$(RESET)\n"
+
+validate-kustomize: kustomize-validate-dev kustomize-validate-prod ## Validate all Kustomize configurations
+	@printf "$(GREEN)Kustomize validation completed!$(RESET)\n"
+
+##@ Environment-Aware Deployment
+
+deploy-with-env-dev: ## Deploy to development using environment variables
+	@printf "$(BLUE)Deploying to development with environment variables...$(RESET)\n"
+	@./scripts/deploy-with-env.sh dev apply
+
+deploy-with-env-prod: ## Deploy to production using environment variables
+	@printf "$(BLUE)Deploying to production with environment variables...$(RESET)\n"
+	@./scripts/deploy-with-env.sh prod apply
+
+deploy-with-env-staging: ## Deploy to staging using environment variables
+	@printf "$(BLUE)Deploying to staging with environment variables...$(RESET)\n"
+	@./scripts/deploy-with-env.sh staging apply
+
+undeploy-with-env-dev: ## Remove development deployment using environment variables
+	@printf "$(BLUE)Removing development deployment with environment variables...$(RESET)\n"
+	@./scripts/deploy-with-env.sh dev delete
+
+undeploy-with-env-prod: ## Remove production deployment using environment variables
+	@printf "$(BLUE)Removing production deployment with environment variables...$(RESET)\n"
+	@./scripts/deploy-with-env.sh prod delete
+
+diff-with-env-dev: ## Show development diff using environment variables
+	@printf "$(BLUE)Showing development diff with environment variables...$(RESET)\n"
+	@./scripts/deploy-with-env.sh dev diff
+
+diff-with-env-prod: ## Show production diff using environment variables
+	@printf "$(BLUE)Showing production diff with environment variables...$(RESET)\n"
+	@./scripts/deploy-with-env.sh prod diff
+
+status-with-env-dev: ## Show development status using environment variables
+	@printf "$(BLUE)Showing development status with environment variables...$(RESET)\n"
+	@./scripts/deploy-with-env.sh dev status
+
+status-with-env-prod: ## Show production status using environment variables
+	@printf "$(BLUE)Showing production status with environment variables...$(RESET)\n"
+	@./scripts/deploy-with-env.sh prod status
+
 reset: clean install ## Reset project (clean and reinstall)
 	@printf "$(GREEN)Project reset completed!$(RESET)\n"