feat: add inline canary and batch strategy in RolloutSpec

[youngLiuHY]

Add CanaryStrategy and BatchStrategy fields to RolloutSpec, allowing users to configure rollout strategy directly in Rollout without requiring a separate RolloutStrategy resource. These fields are mutually exclusive with StrategyRef.

1. Does this PR affect any open issues?(Y/N) and add issue references (e.g. "fix #123", "re #123".):

• N
• Y

2. What is the scope of this PR (e.g. component or file name):

3. Provide a description of the PR(e.g. more details, effects, motivations or doc link):

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Other

4. Are there any breaking changes?(Y/N) and describe the breaking changes(e.g. more details, motivations or doc link):

• N
• Y

5. Are there test cases for these changes?(Y/N) select and add more details, references or doc links:

• Unit test
• Integration test
• Benchmark (add benchmark stats below)
• Manual test (add detailed scripts or steps below)
• Other

6. Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

[Copilot]

Pull request overview

Adds inline rollout strategy configuration to the Rollout API by introducing canaryStrategy and batchStrategy fields on RolloutSpec, alongside regenerated API artifacts and CRD manifests.

Changes:

• Extend RolloutSpec with optional inline CanaryStrategy and BatchStrategy fields and relax StrategyRef requirement.
• Regenerate deepcopy code and Rollout CRD to include the new fields in the published schema.
• Add an implementation plan document describing the intended API changes and follow-up work in other repos.

Reviewed changes

Copilot reviewed 3 out of 4 changed files in this pull request and generated 3 comments.

File	Description
rollout/v1alpha1/rollout_types.go	Adds CanaryStrategy / BatchStrategy to RolloutSpec and updates StrategyRef annotations/docs.
rollout/v1alpha1/zz_generated.deepcopy.go	Regenerated deepcopy logic to correctly copy the new strategy pointers.
config/crd/rollout/rollout.kusionstack.io_rollouts.yaml	Regenerated CRD schema to expose canaryStrategy and batchStrategy fields.
docs/plans/kube-api-inline-batch-strategy-plan.md	Adds a repo change plan for inline strategy support and regeneration steps.

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