Update settings.yaml

Use environment variables for NetBox URL

Update settings.py

Update settings.yaml to use environment variables

Implement startup secret check in webhook.py

Refactor webhook signature validation logic

Add SHA512 and HMAC512 functions for signature verification

Enhance webhook signature validation logic

Refactor webhook signature verification method

Modify webhook signature hashing method

Enhance webhook signature verification process

Enhance webhook handling with debug option

Add support for multiple webhook signature formats

Use HMAC for signature comparison in webhook

Refactor webhook signature verification to use hashlib