Add official Yoga compatibility tests

[hyfdev]

Summary

• vendor the unmodified Yoga 3.2.1 JavaScript test snapshot under tests/taffyjs-yoga/yoga-official/, with its exact commit provenance and MIT license
• classify the 85 cases covered by published TaffyJS Different or Unsupported boundaries as required failures while preserving Yoga's 17 upstream skips
• run the same official corpus against both @taffyjs/yoga and @taffyjs/yoga-wasm, and fail closed on every unclassified regression or expected failure that starts passing
• isolate the classifier in dedicated official-test projects and require every classified title to remain active rather than upstream-skipped
• document and differentially fixture the oversized cross-axis auto-margin Difference exposed by the official corpus
• record the snapshot and refresh policy in the Yoga PCR documentation

Coverage

The pinned corpus contains 570 Yoga cases: 468 pass normally, 85 are explicit expected failures, and 17 remain skipped by Yoga. The repository's existing focused compatibility tests remain responsible for the exact replacement behavior of documented differences and rejections.

Validation

• vp run ready
• vp run check:wasm:yoga:api
• full vp run check:wasm
• byte-for-byte comparison of all 37 copied source files and the license against Yoga commit 042f5013152eb81c1552dec945b88f7b95ca350f
• independent correctness and maintenance-simplicity reviews, followed by targeted PASS reviews of every fix

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