Structurally validates an open-JSON turn-detection block into RealtimeTurnDetectionSettings:
only recognized, correctly-typed knobs survive. Returns undefined when nothing valid is present,
so an absent or garbage value contributes nothing (tolerant, like every other cascade input).
Numbers are checked for finiteness only — range policy (e.g. Threshold 0..1) belongs to the
driver that maps them.
Structurally validates an open-JSON turn-detection block into RealtimeTurnDetectionSettings: only recognized, correctly-typed knobs survive. Returns
undefinedwhen nothing valid is present, so an absent or garbage value contributes nothing (tolerant, like every other cascade input). Numbers are checked for finiteness only — range policy (e.g. Threshold 0..1) belongs to the driver that maps them.