- Header: X-Gaiia-Webhook-Signature with t=timestamp,v1=signature format - Signed payload: timestamp.body (not just body) - 5-minute timestamp tolerance to prevent replay attacks - Updated tests to match new 4-arity verify_signature/4
Stage 3 of Gaiia integration: webhook event processing for real-time incremental updates from Gaiia. HMAC-SHA256 signature verification using per-organization secrets stored in integration credentials. Handles account, billing subscription, and inventory item events.
