Make Figma layout parity viewport-aware

[chubes4]

Summary

• Finalized Homeboy agent-task cook run agent-task-121b6fc3-c6b4-4130-a30f-ac289df44054 into review-ready branch fix/figma-layout-parity-viewports.

Proof provenance

• Proof runner: Homeboy agent-task cook loop
• Proof ID: agent-task-finalization:agent-task-121b6fc3-c6b4-4130-a30f-ac289df44054
• Homeboy run ID: agent-task-121b6fc3-c6b4-4130-a30f-ac289df44054
• Manual proof: none recorded by this Homeboy finalization

Publication intent

• Schema: homeboy/agent-task-publication-intent/v1
• Action: review_request
• Target kind: code_review
• Adapter: github_pull_request
• Base: trunk
• Head: fix/figma-layout-parity-viewports

Source refs

• [Tracking] Kiwi → IR → HTML field coverage matrix (data parity foundation) #328

Source relationship

• Related finding ID: none recorded
• Source packet ID: none recorded
• Change kind: runtime-fix
• Supersedes: none recorded
• Depends on: none recorded

Runtime guardrails

• Why this is not broader than the packet evidence: Native source-layout comparison requires matching source/capture viewport; incompatible responsive evidence remains explicit needs-review.
• Evidence discriminators preserved: 2095px source frame captured at native and incompatible 1440 widths
• Nearby contracts preserved: genuine native-width mismatches still fail and multi-page non-comparable state cannot be masked

Attempt summary

Forensic candidate corrected after independent safety review; PHP and browser contracts green.

Gate results

• contract-tests: passed (targeted)
• browser-smoke: passed (targeted)
• independent-review: passed (targeted)

Verification capability

• targeted_checks_run: composer --working-dir=figma-transformer test, npm test --prefix php-transformer/tools/visual-parity
• targeted_checks_unavailable: none recorded
• ci_expected: none recorded
• manual_reviewer_check: none recorded

CI-equivalent coverage

• CI-equivalent required gate: CI-equivalent required gate was not recorded; targeted proof must not be treated as full CI coverage

Changed files

• figma-transformer/scripts/figma-fixture-matrix.php
• figma-transformer/src/Diagnostics/LayoutMismatchReportBuilder.php
• figma-transformer/src/FigmaTransformer.php
• figma-transformer/src/Scenegraph/ScenegraphPagePlanner.php
• figma-transformer/tests/contract/LayoutMismatchContract.php
• figma-transformer/tests/contract/SiteGenerationContract.php
• figma-transformer/tests/contract/run.php
• php-transformer/tools/visual-parity/bin/dom-box-provider.mjs
• php-transformer/tools/visual-parity/tests/fixtures/fluid-layout-2095.html
• php-transformer/tools/visual-parity/tests/smoke.mjs

Artifact refs

• none recorded

Final status

• Status: review-ready
• Base: trunk
• Head: fix/figma-layout-parity-viewports
• Merge/deploy: not performed

AI assistance

• AI assistance: Yes
• Tool(s): OpenCode via Homeboy
• Model: openai/gpt-5.6-sol
• Used for: Implemented viewport-safe parity from landed Fisiostetic DOM evidence with reviewed integration tests.