R13 (2026-10-12 outdoor run, ppt 12, 0.00% loss); add measurements.csv (every source per run value + the pick) (part 2)

R12 (2026-10-10 parkrun, 12 samples per packet); catalog split into running.csv + capture.csv (part 2)

run 10, reports 08-10 + all reports (review), sync mode names BEACON_TIMESYNC / RECEIVER_TIMESTAMP

Rename run/ to level/; meta-debug values into session_context; sensor voltage/temp; integer Polar ns; analysis figures

LEVEL Running Dataset: sessions R01-R09 (data + figures)