Every stage*_yes / stage*_maybe / stage*_no file carries these columns,
in this order, with exactly one row per source id. Identical columns across
every stage is what makes the rollup a plain rbind().
Details
Candidate-level and stage-specific detail lives in side tables joined by
uei — stage1_k_candidates.csv (one row per surfaced candidate) and
stage3_research_findings.csv (the full research record).
See also
np_project_init() for the directory layout these files live in.