feat(data): calibrate agent readiness evidence

[auscaster]

Summary

• add production-shaped positive and negative readiness controls
• bind the initial cohort to exact service-use evidence roles and stable first-party sources
• close pricing, eligibility, error, billing, and applicability evidence gaps found by the population audit

Proof

The Sourcey population gate reconstructed this exact full vendor tree and proved 20 vendors / 22 profiles with 253 captures, 352/352 covered graded signals, 101/101 classified barriers, an A+ positive control, and a D negative control. The public repository remains declaration-only; grades and evidence stay in Catalog authority.