Conformance: resolve the 14 non-JIT PR-249 reference cases

[chrisbbreuer]

Parent: #143
Roadmap: #134
Depends on completed #144, #145, #265, #287, and #403

The pinned PR-249 inventory has 14 reference-only executables that do not depend on the optimizing JIT. Their declared blockers are shared/concurrent-GC shell controls, Wasm/buffer lifetime, TypedArray race semantics, heap-snapshot/mark-list diagnostics, and two explicitly incompatible JSC premises.

Exact scope

• api/wasm-refused-sd7.js
• congc-t{2,3,4,5,8,9,11}-*.js
• cve/mc-df-arraycopy-relabel.js
• cve/mc-gc-weakgcmap-registry-vs-prune.js
• cve/mc-grow-buffer-storm.js
• cve/mc-life-creator-thread-dies.js
• dw2-marklistset-storm.js
• w16-c1-prevent-collection.js

Acceptance

• Run every exact file under the relevant default and no-GIL modes and record its current pass/fail/timeout premise.
• Promote cases whose portable behavior is now implemented; do not add fake $vm no-ops merely to reach trailing sanity checks.
• Implement maintained shell controls only when they expose real zig-js GC/Wasm/buffer behavior with deterministic semantics and tests.
• Give JSC-private or intentionally incompatible premises a versioned terminal disposition that the verifier distinguishes from an unexplained skip.
• Preserve TypedArray detach/grow rules, weak/finalization behavior, heap-snapshot consistency, GC coordination, and Wasm backing lifetime.
• Update the machine-readable inventory, allowlists, probes, docs, and exact counts together.
• Pass focused cases, the reference audit, normal/no-GIL tests, and only then the relevant TSan batch.

Completion evidence

Completed on main in e6d15b1e and documented in fa71b012.

• 8 portable cases are promoted and pass exact ReleaseFast default/no-GIL execution plus TSan.
• 6 JSC-private or intentionally incompatible premises have structured terminal dispositions and executable outcome probes.
• The checked-in inventory now reports 243 promoted, 10 optimizing-JIT blocked, and 6 terminal executables out of 259; all 339 files and 5 helpers remain classified.
• $vm.createGlobalObject() now creates a real shared-VM child realm and publishes it under the parallel-JS realm lock.
• Focused realm tests pass 3/3; the reference audit passes 7/7 drift self-tests; all 5 bounded terminal probes confirm their declared outcomes.
• Exact per-case normal/no-GIL/TSan evidence is committed at docs/.data/pr249-non-jit-resolution-2026-07-21.json.

[chrisbbreuer]

Completed on main in e6d15b1 and fa71b01. Eight portable cases are promoted with exact default/no-GIL/TSan evidence; six JSC-private or intentionally incompatible premises now have verifier-enforced terminal dispositions and bounded outcome probes. The focused post-rebase realm test and PR-249 audit/probe gate pass.