[woksin]

Added

• Guards can opt in to strict operand checking for Contains, by setting guards: { strictOperands: true } on the InteractionScope context. In strict mode, a null or missing field evaluates to false, and the fallback runs. A collection, number, boolean, object or other non-string operand is reported as unevaluable, so neither the command nor the fallback runs. Without the setting, Contains behaves exactly as before. (Enforce Screenplay string-only contains semantics in native guard selection #276)

[woksin]

Reviewer notes

• Contract decision (L0, under woksin's delegation): in strict mode, a null or missing field in Contains(string) evaluates to false, following Screenplay's documentation (Documentation/screenplay/screens.md, lines 86–90, "Subject and conditions"). Unsupported non-string operand shapes are unevaluable (SCENE-GUARD-001). The type check runs on the raw operands, before enumeration normalization.
• Paths covered: native guard selection for core:guarded-action, interaction alternatives (runActions/branchActions), every useInteractions path including interval findings, and the click-time recheck in CoreGuardedAction.
• Local: full yarn ci and yarn verify-packages passed at d2660ca. Under heavy load, one yarn ci run timed out on the unrelated primereact/for_editor/when_sanitizing_hostile_html spec, which has a 5 s limit. It passes at normal load (see Show why a guarded command failed #278 notes).
• Review: one full round passed. One quick delta round for the enumeration fix also passed. A non-blocking advisory was left as is: the numeric-ordinal spec could discriminate more sharply.
• Consumer: Stage enables guards: { strictOperands: true }. L51 will run the Stage proof inside the train-8 candidate using locally packed tarballs from this commit. Stage won't move to this version until that proof passes.