PASS actual sendDoc emits complete long UTF-8 frame despite SDK max-length truncation
PASS failed notification is separated from retried complete frame
PASS USB output remains a complete NDJSON frame
SKETCH_FUNCTION_SHA256 409900299c5d7cbacce0ee6c05279c5592f88f4541866878df545d7f35b6d02a
Scope: host execution of actual output function; no GPIO, BLE controller or RF access
