what about the generic chat kind 9? https://github.com/nostr-protocol/nips/blob/master/C7.md it's used in NIP-29 (h-tagging group id) and could work for repos (a-tag repo and h-tag for channel?) cc no...
What channel? Repositories have channels? I think just a kind:9 with an "a" tag might be ok, not sure.
The entire question to me revolves around what relays to use for the chat, and who is going to moderate it, because eventual consistency doesn't work for live chat, we need close to absolute consistency.
For threaded comments kind:1111 is good and it should use both the owner's inbox relays and the repository relays, but for chat we should all agree on a single source of truth, perhaps the repository announcement could define that.
The entire question to me revolves around what relays to use for the chat, and who is going to moderate it, because eventual consistency doesn't work for live chat, we need close to absolute consistency.
For threaded comments kind:1111 is good and it should use both the owner's inbox relays and the repository relays, but for chat we should all agree on a single source of truth, perhaps the repository announcement could define that.