0b8350c770
Paddle sandbox sends lifecycle events (subscription.updated, etc.) with
"custom_data": null. The .get("custom_data", {}) default only applies
when the key is missing, not when the value is explicitly null, causing
AttributeError on the next .get() call. Also guarded subscription.activated
to skip when user_id is absent (was inserting user_id=0 → FK violation).
Replaced manual HMAC verification with paddle_billing.Notifications.Verifier
via a lightweight _WebhookRequest wrapper satisfying the SDK's Request Protocol.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>