Ref #166 Phase 1: Add RoleBasedGroup apiVersion v1alpha2

Ⅰ. Motivation

Ⅱ. Modifications

Phase 1: Add RoleBasedGroup apiVersion v1alpha2

1.1 Deprecate Workload Field

Goal: Simplify API by removing the burden of explicitly specifying workload type

• Mark workload field as deprecated
• Controller automatically infers workload type internally

1.2 Change Default Workload Type to InstanceSet

Goal: InstanceSet as the default and recommended workload type

• v1alpha2 uses InstanceSet workload by default

1.3 Redefine Role Template Declaration for Standalone/Multi-node Topology

Goal: Use Pattern model to clearly distinguish standalone and multi-node deployment

Completed Work:

• Introduce Pattern structure with standalonePattern and leaderWorkerPattern
• TemplateSource encapsulates template and templateRef
• TemplateRef encapsulates name and patch fields
• Remove top-level template, templateRef, templatePatch fields from RoleSpec
• Remove leaderWorkerSet field, replaced by leaderWorkerPattern

v1alpha2 RoleSpec New Structure:

roles:
  - name: worker
    replicas: 2
    standalonePattern:           # Standalone mode
      template: {}               # Or use templateRef
      # templateRef:
      #   name: "shared-template"
      #   patch: {}
    # Or
    leaderWorkerPattern:         # Multi-node mode (LeaderWorkerSet)
      size: 4
      template: {}
      leaderTemplatePatch: {}
      workerTemplatePatch: {}

1.4 Temporarily Remove PodGroupPolicy / CoordinationRequirements Fields

Goal: Decouple gang scheduling and coordination into independent CRDs

• Remove podGroupPolicy field from v1alpha2 RoleBasedGroupSpec
• Remove coordination field from v1alpha2 RoleBasedGroupSpec

1.5 Use v1alpha1 as Storage Version

Goal: Ensure backward compatibility and smooth transition

• Mark v1alpha1 with +kubebuilder:storageversion
• v1alpha2 does not set storageversion (served but not stored)

Ⅲ. Does this pull request fix one issue?

fixes #XXXX

Ⅳ. List the added test cases (unit test/integration test) if any, please explain if no tests are needed.

Ⅴ. Describe how to verify it

VI. Special notes for reviews

Checklist

• Format your code make fmt.
• Add unit tests or integration tests.
• Update the documentation related to the change.