Consolidate duplicated transport streaming settings (~530 LOC)

[lanycrost]

Summary

Transport streaming settings are duplicated across `api/v1alpha1` and `api/transport/v1alpha1` (~530 LOC). Consolidate to a single source.

Problem

Maintaining two copies of the same types creates drift risk and complicates the adapter layer in `pkg/transport/settings.go`.

Proposed change

• Consolidate to a single type definition in one API group
• Remove the adapter layer
• Requires a CRD schema change (coordinate with migration strategy)

References

• Roadmap: https://bubustack.io/docs/community/roadmap (Operator maintenance backlog)