Safety mesh — youth tier defaults

Youth-tier programs (Youth League, Travel Club, sometimes School Athletics) ship with safety defaults that don't apply to college / pro.

Defaults:
1. **Coach SafeSport certification (enforced)** — a coach cannot be assigned to a team unless a current SafeSport certificate is on file for them. Enforcement is on by default for Youth League, Travel Club and School Athletics; College and Pro tiers must switch it on explicitly.
2. **Film moderation** — every film clip uploaded on the org side flows through the platform image-moderation pipeline (`onImageUploaded` → `moderationStatus`). Clips pending review aren't visible to athletes / parents until reviewed.
3. **Parent / guardian gate** — for athletes under 13, all athlete-facing UI is parent-mediated. The parent's account is linked to the minor's via the Guardian module; parents control consent for film visibility, talent-network opt-in, recruiting contact, etc.

**Not yet built:** coach↔minor messaging is NOT audited today. The Safety Mesh signal bus exists and audits image moderation, but no messaging path publishes to it. Do not staff on the assumption that coach messages are logged.

Pro tier turns these off by default (different legal regime).