PublishLowPriority uses trySendMsg to silently drop messages when a
client's buffer is full, instead of disconnecting them. This provides
priority-based backpressure: chat messages use normal Publish (disconnect
on overflow), while ephemeral events like typing indicators and presence
updates use PublishLowPriority (drop on overflow).
https://claude.ai/code/session_01CBFF3r84ywkJRWwuqw8zD8