docs: fix outdated Region size in multi-AZ deployment doc

[doc-claw-bot]

What is changed, added, or deleted? (Required)

• Update multi-data-centers-in-one-city-deployment.md to use the current default Region size (256 MiB) instead of the outdated 96M.
• Keep the Chinese page aligned with the English source page for the same fix.

Which TiDB version(s) do your changes apply to? (Required)

Tips for choosing the affected version(s):

By default, CHOOSE MASTER ONLY so your changes will be applied to the next TiDB major or minor releases. If your PR involves a product feature behavior change or a compatibility change, CHOOSE THE AFFECTED RELEASE BRANCH(ES) AND MASTER.

For details, see tips for choosing the affected versions (in Chinese).

• master (the latest development version)
• v9.0 (TiDB 9.0 versions)
• v8.5 (TiDB 8.5 versions)
• v8.1 (TiDB 8.1 versions)
• v7.5 (TiDB 7.5 versions)
• v7.1 (TiDB 7.1 versions)
• v6.5 (TiDB 6.5 versions)

What is the related PR or file link(s)?

• Related code change PR links (if applicable):
• This PR is translated from: docs: fix outdated Region size in multi-AZ deployment doc docs#24204
• Other reference link(s):

AI agent involvement

• The changes in this PR were primarily made by an AI agent on behalf of the PR author.

Do your changes match any of the following descriptions?

• Delete files
• Change aliases
• Need modification after applied to another branch
• Might cause conflicts after applied to another branch

Summary by CodeRabbit

• 文档
  • 将 TiKV Region 的默认大小更正为 256 MiB。

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

• Configuration used: Repository: pingcap/docs-cn/.coderabbit.yaml
• Review profile: ASSERTIVE
• Plan: Advanced
• Run ID: 8c3884ce-540f-4a0f-a633-3c7f288960c9

📥 Commits

Reviewing files that changed from the base of the PR and between b7adc67 and 3278aa0.

📒 Files selected for processing (1)

• multi-data-centers-in-one-city-deployment.md

Included review availability: This review used your included allowance. Your plan provides up to 4 included reviews per hour; 3 remain after this review.

---

📝 Walkthrough

Walkthrough

文档将 TiKV Region 默认大小从 96M 更正为 256 MiB。

Changes

Region 默认大小文档

层 / 文件	摘要
更正文档中的默认大小 multi-data-centers-in-one-city-deployment.md	将 TiKV Region 默认大小从 96M 改为 256 MiB。

Priority: ⬇️ Low

Estimated code review effort: 1 (Trivial) | ~2 minutes

Change: Other

Merge Risk: ⚪ Minimal · up to 3278a

The deployment guide now matches the documented default for the stated versions. This is a documentation-only correction, with no material merge risk indicated.

Architecture Summary

Architecture risk: 🔵 Low · up to 3278a

The change affects 1 system.

Changed systems: multi-data-centers-in-one-city-deployment.md

Architecture concerns
No architecture-level concerns identified.

Review details

Systems and components

• observed — multi-data-centers-in-one-city-deployment.md (service) was modified; 1 changed file maps to changed impact.

Before / after behavior

• observed — Modified behavior in multi-data-centers-in-one-city-deployment.md: 将 TiKV Region 的默认大小从 96M 更新为 256 MiB。

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	标题准确说明了文档更新的主要内容：修正多可用区部署文档中的过时 Region 大小。
Description check	✅ Passed	描述已说明变更内容和适用版本，并提供英文源 PR 链接及 AI 参与情况。必填信息完整。
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 0…
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create a new PR

• Autopilot · Keep fixing CodeRabbit findings and required CI, and resolving merge conflicts

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by:
Once this PR has been reviewed and has the lgtm label, please assign lilin90 for approval. For more information see the Code Review Process.
Please ensure that each of them provides their approval before proceeding.

The full list of commands accepted by this bot can be found here.

Details

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment