EXPECTED CONDITIONS ONLY, NOT AN EXECUTION LOG.
Start in a new folder with no api_health.csv.
Server running: host=127.0.0.1:8000, http_status=200, sample_bytes=3, result=PASS, error_type empty.
After stopping this server and before another process uses the port: host unchanged, http_status empty, sample_bytes=0, result=FAIL, error_type=URLError.
The fixed response is the three ASCII bytes OK followed by LF. Timing and checked_at_utc are real measurements and have no fixed expected values.
Two probe invocations append two data rows under one header. Existing older rows are preserved, so a previously used file does not have an expected total of two.
Column order: checked_at_utc,host,http_status,elapsed_ms,sample_bytes,result,error_type.
A recorded FAIL is a diagnostic result. STOP indicates a preparation/storage error; do not treat a partial CSV as complete.
