Carry document metadata in WordPress site plans

[chubes4]

Summary

• Extend blocks-engine/wordpress-site-plan/v2 with normalized per-document metadata and generic reporting summaries.
• Resolve local metadata references through the existing canonical token/write contract.
• Preserve browser script loading and standard link/script attributes accurately.
• Add an independent plan-plus-receipt projection contract so consumers can build reports without legacy compiler envelopes.

Closes #639
Relates to #632

What changed

• Added ordered document title, meta, link, and script declarations with source/placement context.
• Preserved quoted, unquoted, empty, boolean, and mixed-case HTML attributes through a bounded parser.
• Modeled async, defer, async+defer, module, nomodule, inline, head/body, and effective browser loading independently.
• Preserved standard attributes including integrity, crossorigin, referrerpolicy, as, fetchpriority, type, and media; empty crossorigin normalizes to anonymous.
• Added generic source/block/fallback/provenance/diagnostic reporting summaries.
• Added exact page/write correspondence validation for plan-plus-materialization-receipt projection.
• Documented the generic consumer boundary; destination report paths and product envelopes remain downstream-owned.

How to test

1. Run composer --working-dir=php-transformer validate --strict.
2. Run php php-transformer/tests/contract/wordpress-site-plan.php; expect wordpress-site-plan contract passed.
3. Run composer --working-dir=php-transformer test; expect all contracts, 244 parity fixtures, and package-install proof to pass.
4. Run git diff --check origin/trunk...HEAD.

The existing required WordPress 6.7.4/MySQL integration job remains enabled alongside the full Composer gate.

Compatibility

This is additive to WordPressSitePlan v2 from php-transformer v0.4.0. Existing v2 fields and resolver behavior remain unchanged. Consumers can ignore the new metadata/reporting fields; consumers needing stable import reports can now project them from resolved plan plus receipt without reading TransformerResult, compiled_site, MaterializationView, raw HTML, source files, or private envelopes. Intended release: v0.4.1.

AI assistance

• AI assistance: Yes
• Tool(s): OpenCode with OpenAI GPT-5.6 Sol
• Model: openai/gpt-5.6-sol
• Used for: Contract design, implementation, standards edge-case analysis, deterministic tests, documentation, and independent review with Chris Huber.