Add JuiceFS Gateway operator support

[Copilot]

Adds a new Gateway CRD that runs juicefs gateway as a Kubernetes Deployment + Service, exposing a JuiceFS volume as an S3-compatible API.

New CRD: Gateway (juicefs.io/v1, shortName: gw)

Supports both editions:

• EE: secretRef → runs juicefs auth <volume> then juicefs gateway <volume> <addr>
• CE: metaURL → runs juicefs gateway <meta-url> <addr> directly

Key spec fields: image, replicas, address (default 0.0.0.0:9000), options, serviceType, resources, tolerations, affinity, nodeSelector.

apiVersion: juicefs.io/v1
kind: Gateway
metadata:
  name: my-gateway
spec:
  image: juicedata/mount:ee-5.1.1-1faf43b
  replicas: 1
  secretRef:
    name: juicefs-secret
  address: "0.0.0.0:9000"
  serviceType: ClusterIP

Implementation

• api/v1/gateway_types.go — CRD type definitions; deepcopy auto-generated
• pkg/builder/gateway.go — builds Deployment (with auth+gateway shell command) and Service
• internal/controller/gateway_controller.go — reconciles Deployment + Service, reflects ReadyReplicas/Replicas into .status.phase (Progressing / Ready)
• cmd/app/controller.go — registers the GatewayReconciler
• config/crd/bases/, config/rbac/role.yaml, dist/crd.yaml — regenerated manifests