Complete walkthrough per provider — signup URL, free-tier details,
pay-per-use pricing, env-var name, key format — plus sections on where
to paste keys (.env.secrets), BYO-keys vs server-keys, verification
curl commands and troubleshooting (including the cross-service
MANA_SERVICE_KEY mismatch encountered during live testing).
Linked from services/mana-research/CLAUDE.md.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
