GET /api/v1/ticket_replies/read.php and POST create.php, so an RMM or
monitoring system can append to a ticket it did not open.
Replies default to Internal so an integration cannot email a client by
omitting a parameter. Public replies mark first response, notify the
contact and watchers, and fire the same custom actions as the agent
reply handler. An optional ticket_status also sets the status, and
resolves the ticket and marks the resolution SLA when set to 4.
Replies are always joined to tickets so ticket_client_id is checked
against the key user's client scope, and the client_id named on a write
must match the ticket's own client. The reply is attributed to the user
the API key runs as.
read.php resolves ticket_reply_by_name, since that column holds a
user_id on Internal and Public replies but a contact_id on Client ones.
