Release Notes 26.0.0

This version improves DDC lifecycle management and reliability, including graceful shutdown rollout for compute groups, configurable readiness probe policies, DCR mTLS support, and clearer DDC health reporting. It also enhances Helm chart configuration and adds several validation and stability fixes.

## Features & Enhancements

- DDC compute groups support graceful shutdown rollout for rolling updates, scale-down, and delete operations, with a sentinel compatibility gate and fallback to the normal StatefulSet flow for unsupported images. #502
- Support configurable readiness probe policy for DorisCluster and DorisDisaggregatedCluster pods. #486
- Support mTLS for DCR. #483
- Split DDC compute group service into an internal headless service and an external service for smoother upgrades and traffic switching. #484
- Helm chart adds support for component-level secrets. #465
- Helm chart exposes serviceAccount configuration for deployed pods. #470

## Bug Fixes

- Fixed DDC MetaService health aggregation so MetaService degradation is reflected in cluster health status. #500
- Fixed nil map panic in `CompareConfigmapAndTriggerRestart` when `dcr.Annotations` is nil. #493
- Fixed FE endpoint address JSON tag and regenerated DorisCluster CRDs. #497
- Reject invalid DorisDisaggregatedCluster FE specs where `feSpec.replicas < feSpec.electionNumber`. #498
- Reject DDC compute group storage template changes before applying immutable StatefulSet volume claim templates. #496
- Fixed the default `storage_root_path` in the DorisDisaggregatedCluster BE Helm config. #477

## Improve & Reliability

- Reject using the built-in `admin` account as the operator management user in DorisCluster and DorisDisaggregatedCluster webhooks. #499
- Add pull request checks for Go formatting, vet/lint checks, operator build, and generated manifests/artifacts. #501

## Thanks

- [ecniiv](https://github.com/ecniiv)
- [jonasbrami](https://github.com/jonasbrami)
- [catpineapple](https://github.com/catpineapple)
- [JinVei](https://github.com/JinVei)
- [Al-assad](https://github.com/Al-assad)

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