Chat transcript assignment for missed chats

A chat transcript record is created for every incoming chat.
Missed chats are assigned to the last agent to whom the chat was assigned. They are assigned to an Automated Process user when the Agent's session cannot be found or is no longer available, or if there is no assigned Agent (in the case of "No Available Agents"), and we need to upsert the record using the system user Automated Process. This also applies when an Agent logs out after a Chat Session is established or rejects the chat and no other agents are available.

For example, a transcript would be assigned to the Automated Process user when the transcript events include: 
1. Visitor requested chat
2. Chat request canceled because no qualifying agents were available
3. Visitor left chat