ACTIVE MEMBRANE CHECK (derived from a prior escape in this domain): When code emits a JSON Schema for OpenAI/codex strict structured outputs, strictness is RECURSIVE. EVERY object node — including every NESTED object — must set "additionalProperties": false AND list EVERY one of its properties in "required". A schema that is strict only at the top level (a nested object left without additionalProperties:false and a complete required list) is REJECTED by OpenAI strict mode. Verify each nested object node, not just the root.
