[chubes4]

Summary

Refs #3689. Completes slice 4 by separating image scoping from semantic identity, preserving author-rule subjects and specificity. Remaining slices cover site-wide declaration addressing, shared chrome, cascade/responsive geometry, editor asset isolation, and dead CSS/class pruning.

What changed

• Stamp every emitted core/image figure with a factory scope; project unscoped image arms through zero-specificity :where().
• Remove class-less image identity discovery while retaining semantic wrapper behavior, existing !important declarations, and the navigation empty-class fix.
• Scope ID-only navigation compatibility replay through existing importer navigation classes.
• Add image-scope regression coverage alongside unchanged responsive browser fingerprints.
• Update exact expectations only: image markup gains its factory scope, code markup its committed source scope, and social CSS its committed cluster scope; editor snapshot provenance remains unchanged.
• Additive importer classes replace unscoped selector arms without changing author-projection specificity or ownership. Existing behavioral assertions remain intact.

Verification

• passed on d243d34. Base trunk@62d5dd5 advanced to 61bcdf1.

export COMPOSER_PROCESS_TIMEOUT=1200
cd php-transformer && composer install --no-interaction -q && composer test

• CI: pending

Cook run

• Gate 1: tree 8acc3d7eec65e747388ce2d56cd7710ddc38f7a2, fingerprint dce08da68f6d4b3b364dd4f171d58ae8d683d2ccb3b4330f7601b39f9e7e8acf
• External proof authorized by operator.
• Publication identity: ambient_gh
• Recovery retained 1 infrastructure-invalid gate record(s).
• Replacement proof covers 1 gate(s).

AI assistance

Tool: Homeboy (pi) · Model: gpt-6.1-sol (tier roadie/cook-heavy) · Used for: cook-heavy via Pi inspected the implementation, edited code and exact expectations, added regression coverage, and ran the full passing suite.

Operator follow-up by Claude (Anthropic) via Roadie: the new compile-time scoping assertion re-parsed every emitted stylesheet, making staged-artifact-compilation ~1.7x slower than trunk (549s vs 319s on the same host). The follow-up commit memoizes verdicts per distinct stylesheet and per selector (252s, trunk parity) without weakening the check.

A second follow-up keeps the social-links support rules at their unscoped specificity by scoping through :where(.blocks-engine-social-source-cluster). The plain class had outranked the source-row display:contents rule and restored the list's UA margin, adding 25px to the scoped dropdown panel (scoped-mixed-dropdown-browser, 234px vs source 209px; now 0 deltas). Topology baseline labels refreshed (counts and scores unchanged).

Refs #3689