Function local_frame_set_enabled_override 

pub fn local_frame_set_enabled_override(v: Option<bool>)

Test/harness-only: force the target/env fallback on/off, or None for the target default. A router constructed with an explicit frame policy does not consult this process-global hook. Mirrors rect_fast::param_set_enabled_override. The mesh-output determinism manifest uses it to run native and wasm with the SAME flag state (wasm defaults ON, native defaults OFF below), so the two targets’ outputs are comparable byte-for-byte.