docs: use ticdc-version variable in TiCDC examples

[doc-claw-bot]

What is changed, added or deleted? (Required)

• Add ticdc-version to variables.json
• Replace hard-coded / TiDB-coupled TiCDC example versions in ticdc/ticdc-architecture.md with v{{{ .ticdc-version }}}
• Keep the release-threshold statements (v8.5.4 / v8.5.4-release.1) unchanged and update only example snippets and example commands

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

• master (the latest development version)
• v8.5 (TiDB 8.5 versions)
• v8.4 (TiDB 8.4 versions)
• v8.3 (TiDB 8.3 versions)
• v8.2 (TiDB 8.2 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)
• v6.1 (TiDB 6.1 versions)
• v5.4 (TiDB 5.4 versions)
• v5.3 (TiDB 5.3 versions)

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

• This PR is translated from:
• Other reference link(s): Ask Docs thread about using a dedicated TiCDC version variable because TiCDC release cadence might diverge from TiDB

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

• Documentation

  • Updated TiCDC deployment examples to use a configurable version placeholder instead of fixed version numbers.
  • Applied the placeholder consistently across TiUP and TiDB Operator scenarios.

• Configuration

  • Added the TiCDC version setting, currently set to 8.5.8.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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📥 Commits

Reviewing files that changed from the base of the PR and between 75a79ad and 318d213.

📒 Files selected for processing (2)

• ticdc/ticdc-architecture.md
• variables.json

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

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📝 Walkthrough

Walkthrough

The change adds the TiCDC version to variables.json and updates five TiCDC architecture deployment examples to use the ticdc-version template variable.

Changes

TiCDC version templating

Layer / File(s)	Summary
Version configuration and deployment examples variables.json, ticdc/ticdc-architecture.md	variables.json adds ticdc-version with value 8.5.8. Five TiDB Operator and TiUP examples now use v{{{ .ticdc-version }}} instead of hardcoded TiCDC versions.

Estimated code review effort: 1 (Trivial) | ~5 minutes

Merge Risk: ⚪ Minimal · up to 318d2

This change only updates TiCDC documentation examples to use a dedicated version variable, with release-threshold statements preserved. No actionable merge-blocking risk remains beyond normal checks and review.

Suggested reviewers: qiancai, ti-chi-bot

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title is concise, clear, and directly identifies the main change: using the dedicated ticdc-version variable in TiCDC examples.
Description check	✅ Passed	The description explains the changes, identifies the affected TiDB version, and provides related context. It omits the AI agent involvement section and uses version checklist entries that differ from …
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.

Full details: Description check

Explanation

The description explains the changes, identifies the affected TiDB version, and provides related context. It omits the AI agent involvement section and uses version checklist entries that differ from the repository template, but the required content is mostly complete.

Full details: Docstring Coverage

Explanation

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 files. (2 skipped: 2 unsupported.)

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[ti-chi-bot]

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[qiancai]

/approve

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: qiancai

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Details

Needs approval from an approver in each of these files:

• OWNERS [qiancai]

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[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch master: #23729.
But this PR has conflicts, please resolve them!