Decide the Explorer threshold: 3, not 2

Three independent sources in the client's own material say Explorer requires 3 qualifying webinars, not the 2 recorded in pm/reference/domain-knowledge-from-spreadsheet-rebuild.md line 23 and AGENTS.md: 1. Certificates_Summary in her workbook lays webinars across columns N..Y as 'Webinar 1'..'Webinar 12' with four group headers: N1 EXPLORER (1-3), Q1 STAR (4-6), T1 SUPERSTAR (7-9), W1 CHAMPION (10-12). 2. Her Process Recap sheet: 'Si not found es porque no habian llegado a tres webinarios y ahora llegaron.' 3. Her answer on 2026-10-08: 'Son 3 webinarios por certificado. Hay 4 niveles. No pueden tener un certificado si no completaron los 3 de ese nivel.' Behaviour agrees: of 256 Explorer sends, 197 went out at exactly 3 and only 12 at 2. The 12-at-2 is the same off-by-one cluster that appears at every other tier (12 Star at 5, 1 SuperStar at 8, 5 Champion at 11) - thin attendance sheets, not a lower threshold. The recorded 2 looks like min(count at send) over a set that cluster poisons. Consequence of leaving it at 2: Explorer's block is 2 webinars wide, so the app prints 'Has attended 2 Career Webinars' with two lines where her own Explorer template for robert4asiedu@gmail.com prints 3 and three. Star's block becomes 4 wide. Consequence of changing it: pending Explorer drops 158 -> 6 (152 people at exactly 2 qualifying stop being pending). No certificate is clawed back - sends stay recorded. Not done on my own: it is a production write that changes who gets a certificate. The operator can flip it in /configuracion. If approved, AGENTS.md, pm/project-background-scope-and-posible-mvp.md and pm/reference/domain-knowledge-from-spreadsheet-rebuild.md all carry the 2 and need the same edit.