feat: add inline canary and batch strategy in RolloutSpec (#49)

* feat: add inline canary and batch strategy in RolloutSpec

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.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* fix: add cross-field validation and fix plan doc path

- Add XValidation rules to enforce mutual exclusivity between
  StrategyRef, CanaryStrategy, and BatchStrategy fields
- Fix plan document path from apis/rollout/v1alpha1/types.go
  to rollout/v1alpha1/rollout_types.go

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

* feat: rollout spec support webhook

* feat: rollout strategy support refined batch strategy && remove rollout batch strategy

* fix: adjust the structure and rename some fields

* fix: remove outdated plan

---------

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: youngLiuHY

config/crd/rollout/rollout.kusionstack.io_rollouts.yaml

@@ -70,7 +70,7 @@ spec:
                 format: int32
                 type: integer
               strategyRef:
-                description: StrategyRef is the reference to the rollout strategy
+                description: StrategyRef is the reference to the rollout strategy.
                 type: string
               trafficTopologyRefs:
                 description: |-