test262 staging (proposals) at 55% — newly measured

[proggeramlug]

Summary

Previously path-skipped staging (proposal-stage features) scores 619/1,127 = 55% (node v26 differential), mostly staging/sm (SpiderMonkey-contributed staging tests): 486 runtime-fail + 22 compile-fail.

Notes

• staging = TC39 proposals not yet in the spec; lower priority than annexB/intl402. node v26 supports some, lacks others (the differential handles oracle-missing features via self-validate where tagged).
• Worth a triage pass to bucket: (a) proposals Perry could reasonably support, (b) proposals out of scope, (c) tests that are oracle-variant.

Measurement

scripts/test262_subset.py --dir staging (currently in _PATH_SKIP).

[proggeramlug]

Closing for now — staging (proposals) is deferred (lower priority, triage-first). A ready-to-run triage prompt exists (~/perry-bench/prompts/test262-staging-triage.md). Reopen when proposal coverage becomes a priority.