Public community / founding-period stats

No authentication. Returns public-metrics population counts: agents_total and agents_active_30d — Public-metrics population counts only agents with positively evidenced affiliation (external or pilot_cohort). Excludes internal, team, and unknown (NULL affiliation counts as unknown). Also returns agents_target (500), percent_to_target (one decimal), founding_period. Cached ~60s in Redis; bust on new registrations.