cloud: add 20251021 release notes

[qiancai]

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[gemini-code-assist]

Summary of Changes

Hello @qiancai, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request introduces the latest release notes for TiDB Cloud, specifically for October 21, 2025. The updates primarily focus on enhancing the TiDB Cloud Dedicated offering by significantly improving the private endpoint capabilities for Changefeeds, making configuration simpler and more secure, and by introducing a preview of Prometheus integrations to provide advanced, cluster-level monitoring and alerting.

Highlights

• Private Endpoint Enhancements for Changefeeds: The private endpoint feature for TiDB Cloud Dedicated Changefeeds has been significantly enhanced, offering simplified configuration by allowing independent creation and sharing across multiple changefeeds. It also introduces private link sinks for MySQL, enabling secure data transfer, including to other TiDB Cloud Dedicated clusters, and supports custom domains for self-hosted Kafka services.
• Prometheus Integrations (Preview): Prometheus integrations are now available in preview for TiDB Cloud Dedicated clusters. This feature provides cluster-level management for shipping metrics to Prometheus, allowing for more granular control and advanced alerting capabilities.
• New Release Notes Entry: A new section for the October 21, 2025 release notes has been added to the tidb-cloud-release-notes.md file, detailing the aforementioned enhancements.

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[gemini-code-assist]

Code Review

This pull request adds release notes for October 21, 2025. The changes are well-written and clear. I've made a couple of minor suggestions to improve grammatical correctness and maintain consistency with linked documents. Overall, great work.

[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2025-10-21 03:52:40.853298337 +0000 UTC m=+757466.930550897: ☑️ agreed by hfxsd.

[qiancai]

/approve

[ti-chi-bot]

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This pull-request has been approved by: qiancai

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