2026-06-01-preview-wave-plan (#44842)

* 2026-06-01-preview-wave-plan

* fixes

* Fixes

* Add 2026-06-01-preview entry to Waves service.yaml (regenerated by tsp compile)

* Suppress csharp-model-suffix for new wave plan action models

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Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>