Correct TiCDC Debezium DDL/WATERMARK support reference

[Copilot]

First-time contributors' checklist

• I've signed the Contributor License Agreement, which is required for the repository owners to accept my contribution.

What is changed, added or deleted? (Required)

The TiCDC Debezium doc incorrectly stated that DDL and WATERMARK events are supported starting in v9.0.0. This update replaces that version claim with an architecture-based reference that matches actual product behavior.

• Doc correction

  • Update /ticdc/ticdc-debezium.md to remove the incorrect v9.0.0 statement.
  • State that DDL and WATERMARK events are supported in the TiCDC new architecture.

• Cross-reference cleanup

  • Link the Debezium doc directly to /ticdc/ticdc-architecture.md so the support boundary is defined by architecture, not by an incorrect version marker.

In the [TiCDC new architecture](/ticdc/ticdc-architecture.md), TiCDC supports DDL events and WATERMARK events.

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.

• 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)?

• This PR is translated from:
• Other reference link(s):
  • /ticdc/ticdc-debezium.md
  • /ticdc/ticdc-architecture.md
  • https://github.com/pingcap/ticdc/blob/v8.5.4-release.1/pkg/sink/codec/debezium/encoder.go#L37

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

• Fixes TiCDC Debezium Protocol wrongly claimed DDL/WATERMARK event is supported since v9.0.0 (it is supported since v8.5.4-release.1) #23469

[ti-chi-bot]

Hi @copilot. Thanks for your PR.

I'm waiting for a pingcap member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Details

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[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 ask for approval from lilin90. 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