CDN-222: The Evidence Packet Template

CDN-222 turns the TTY intake chain into an uploadable evidence packet template. It packages eight blank validator-ready files covering manifest, provenance, public c/f timing rows, forecast freeze, holdout residuals, mode coverage, claim attestation, and README instructions. The template inherits the CDN-220 intake schema and CDN-221 claim firewall, but contains zero observed values and pays zero TTY. It is admissible structure only until populated with public c/f evidence and revalidated.