🛠️ [TASK] : `.new` topic

[bkioshn]

Summary

.new topic

Description

Implement the .new topic for document announcements in the Document Sync Protocol. This covers subscription, broadcasting new doc, keepalive, and timers and retries.

Task

1. Subscription

• Subscribe to <base>.new during channel initialization

2. Boardcasting new document

• The pre-publish check should be covered in 🛠️ [TASK]: Hermes needs to run the pre-publish checks before publishing a new document to IPFS PubSub #630
• Boardcasting doc on <base>.new - during post

3. Keep alive mechanism When there is no new doc to be publish, this need to be triggered

3.1 Quiet-Period Timer

• Maintain per-channel quiet-period timer
• Timer duration: uniform random in [20s, 60s] with jitter
• Reset timer when any .new message is received on the channel
• Rate-limit to avoid sending more than one keepalive per Tquiet interval

3.2 Keepalive Publishing

• On timer expire (if no new documents to publish), publish .new with docs=[]

Out of scope notes

• Message envelope construction/verification
• Receiving and processing .new messages