HTML API: Detect CDATA by adjusted node namespace

[sirreal]

Summary

• Keep CDATA detection tied to the adjusted node namespace instead of the integration-point tokenizer namespace.
• Preserve SVG and MathML namespaces for CDATA sections inside HTML integration points.
• Add regression coverage for SVG foreignObject and MathML annotation-xml.

Testing

• Focused PHPUnit coverage for SVG and MathML HTML integration points.
• HTML API PHPUnit coverage and PHPCS pass.
• codex review --base trunk.

Trac ticket: https://core.trac.wordpress.org/ticket/65372

Use of AI Tools

AI assistance: Yes
Tool(s): Codex
Model(s): GPT-5.5
Used for: PR description cleanup and code review.

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This Pull Request is for code review only. Please keep all other discussion in the Trac ticket. Do not merge this Pull Request. See GitHub Pull Requests for Code Review in the Core Handbook for more details.

[sirreal]

Code review

No issues found. Checked for bugs and CLAUDE.md compliance.

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[sirreal]

Code review

No issues found. Checked for bugs and CLAUDE.md compliance.

🤖 Generated with Claude Code

_{- If this code review was useful, please react with 👍. Otherwise, react with 👎.}