Add lurk setting to avoid showing up in read by (readby)
Currently anyone in a channel I am member of can see whether I've seen a post or not via the "Read by" in the top-right of any message.
I think it is bad practice to force users to disclose this information. I recommend adding a "lurk" option to control this. Ideally, the option would be opt-in but opt-out is acceptable. It should be possible to enforce this setting across all clients, including the IRC bridge.
Previously, there was lurk setting connected to notifications but it was intertwined with what notifications you saw and not just whether you showed up in the readby list. This was removed when we simplified notifications.