From ARU:

stuff needed in the database for threads:
Ticket
id, created at, who created it (eg a member, or themselves), 

Messages:
author
server_message_id
dm_message_id
attachments
embeds
contents
was_internal?

All of thread messages, and attachments links and stuff too, including a ticket and author (user) object


user table: all users who've interacted with modmail
id
default avatar number
name
dm_channel_id

So, schema:
Ticket:

• id (INTERNAL)
• server_id
• thread_id
• creator_id (user ID)
• user_id (target user ID)
• creating_message_id
• creating_channel_id

Messages:

• id (from discord, dm id)
• ticket_id
• mirrored_id (in server message id)
• author_id
• content
• internal

Attachments:

• internal id
• message id
• link

Embeds:

• internal id
• message id
• json content as a bytes field

Emoji: (Later feature)

• id
• url
• animated

emoji_messages:

• emoji_id
• message_id

Configuration:

• server_id
• optional thread_id for thread specific config
• config key name
• config value