al support cloud storage

[shiyuhang0]

New feature

• Support configure rotation policy and cloud storage for audit log with ticloud serverless audit-log config update command.

Break change

• The command ticloud serverless audit-log config is replaced by ticloud serverless audit-log config update.
• The command ticloud serverless audit-log describe is replaced by ticloud serverless audit-log config describe

[pingcap-cla-assistant]

All committers have signed the CLA.

[github-actions]

license-eye has checked 669 files.

Valid	Invalid	Ignored	Fixed
187	1	481	0

Click to see the invalid file list

• internal/cli/serverless/auditlog/ui.go

Use this command to fix any missing license headers

```bash

docker run -it --rm -v $(pwd):/github/workspace apache/skywalking-eyes header fix

</details>

[Copilot]

Pull Request Overview

This PR adds cloud storage support for TiDB Cloud Serverless clusters, enabling audit log storage and backup functionality across multiple cloud providers including S3, GCS, Azure Blob, and Alibaba Cloud OSS.

• Introduces cloud storage models and authentication types for S3, GCS, Azure Blob, and OSS
• Extends audit log configuration to support cloud storage options with rotation settings
• Updates cluster models to remove deprecated usage tracking and refactor high availability types
• Adds support for Alibaba Cloud (Alicloud) private endpoints

Reviewed Changes

Copilot reviewed 86 out of 86 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
Various model files	New cloud storage models for S3, GCS, Azure Blob, and OSS with authentication types
model_v1beta1_cluster_audit_log_config.go	Extended audit log config with cloud storage and rotation settings
model_tidb_cloud_open_apiserverlessv1beta1_cluster.go	Removed usage field and updated high availability type references
model_endpoints_private.go	Added Alicloud private endpoint support
Various auditlog files	Updated API naming from "Serverless" to "Starter and Essential"

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