Implement Network Sync For Direct Messages

[zicklag]

• We need to allow you to open up a direct message channel to another BlueSky user.
• The network sync will happen over the WebSocket routing server.
• Encryption will be done using Tweet NaCl's Box.
• The automerge document for each direct message will be periodically saved off to the user's PDS.
• If the user you want to chat with is not online and connected to the routing server, the client will download the automerge document from the other user's PDS and merge it with their document to get the latest changes.
• We can try to record the automerge version of the document on the user's PDS so that it's easy for the client to tell when there is new data that needs to be downloaded from the PDS.

Note:

• Downloading the whole automerge document from the PDS may not be practical in the long term with long chats, but at the same time, the whole King James Version of the Bible in JSON format is only 4.6M, so it'd be hard to make a prohibitively long chat direct messages anyway for now.

[zicklag]

Realtime sync through the router is now implemented!