blocks-engine 0.2.2: add opt-in structuredStrategy for no-CSS-carry blocks reconstruction

[borkweb]

Summary

Adds structuredStrategy, a selectable reconstruction strategy exported from @automattic/blocks-engine/theme. It interprets the SectionSpec into clean, theme-styled canonical blocks first (nativeDecision → renderCover / renderCardGrid / renderMediaText / …), falling back to a verbatim core/html island only on coverage loss. Unlike the preserve-DOM default it does not preserve source classes or whole-section islands, so its output is self-contained and renders from the theme alone — no dependency on carried source CSS.

Bumps the package to 0.2.2 with a CHANGELOG entry and a strategy-seam test.

Why

The interpretive structured renderers still exist in the engine, but both shipped strategies (defaultReconstructStrategy, classifySemanticStrategy) route through preserve-DOM / verbatim islands first — keeping source classes and therefore requiring carried source CSS to render. A no-CSS-carry blocks pipeline (data-liberation's blocks reconstruct path) had no way to select the structured renderers, so its output rendered unstyled (class-preserving blocks with no backing CSS, e.g. a Wix homepage stacking to ~20× the source height). structuredStrategy restores that pre-preserve-DOM fidelity.

Safety

Strictly additive and opt-in via SectionRenderOptions.strategy. The default remains defaultReconstructStrategy (preserve-DOM), so the carried-CSS paths (local-convert, theme-carry) are byte-identical — verified by the existing strategy-seam byte-identity test and the full suite (441 tests green).

Test plan

• vitest run — full suite green (441), including the new structuredStrategy seam tests and the unchanged default-path byte-identity test.
• Dogfood (data-liberation blocks path, Wix source): structured output is gate-passing with 0 preserved source classes / 0 islands / 0 remote URLs; renders theme-styled chrome + wp:cover hero + gallery columns at ~source height (vs. unstyled stack under the default).