contains? did not support dict key membership in the real runtime —
(contains? {:a 1} :a) threw "contains?: 2 args", contradicting its own :doc.
The fix landed (primitives.sx + sx_primitives.ml) but had no pinning test.
Add suite gate-K20-contains-dict to spec/tests/test-gate-pins.sx (4 tests,
repro from plans/sx-review/core.md): present key true, missing key false,
list membership + string substring unchanged. 8/8 green under OCaml run_tests.
Test-only: no semantics edits, no push.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
The dc7aa709 quick-wins batch fixed `expt`'s silent 63-bit int wrap (now
promotes to float like +/*) but shipped no pinning test — a regression would
pass silently. Add spec/tests/test-gate-pins.sx suite gate-K18-expt-overflow
(4 tests, minimal reprs from plans/sx-review/core.md): small exponents exact,
2^62 and 2^100 do not wrap, 2^100 is a float. 4/4 green under OCaml run_tests.
Also bootstraps plans/agent-briefings/sx-gate-loop.md (the loop's own briefing,
absent until now) with the W14 checklist derived from PLAN.md §W14.
Test-only: no semantics edits, no push.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
