Retired GitHub webhook settings

The Routines model removes the dedicated GitHub webhook listener along with Definitions and Automations. Factory no longer serves /api/v1/webhooks/github.

Existing config.toml files may still contain these retired fields:

• webhook_listen
• webhook_tls_cert
• webhook_tls_key
• github_webhook_secret_file

Factory accepts and ignores them during upgrade so an old configuration cannot prevent the database migration or server startup. Remove the fields after the upgrade. They do not start a listener.

Use a Routine to describe repository work, choose its repositories, and run it manually or on a schedule.