Put ghost participants behind a developer flag

[robintown]

Your use case

What would you like to do?

Hide ghost participants by default, and show them only if a developer flag is enabled.

Why would you like to do it?

Ghosts can show up in normal usage of the app whenever there is a delay between someone leaving the call in Matrix and leaving the call in LiveKit. This is not great, as people will generally not know or care about what the 👻 icon means. I contend that ghost participants are really meant to be a developer feature used for load testing.

How would you like to achieve it?

Wait until we get an E2EE system which selectively shares keys with connected participants via a private channel (i.e. to-device messages). We need to wait for this because currently, showing ghost participants is how we prevent eavesdropping.

Have you considered any alternatives?

No response

Additional context

No response

[schelmo]

it would be great to have some kind of allowlist for livekit identities.
because the cool thing now is, you can send media to element call rooms (of course only if you have api access to your livekit server) e.g. with the livekit-cli .
these participants are currently also marked as [👻]. i assume these would also be hidden then?
maybe we can define an allowlist in the EC config.json?

{
  "livekit": {
    "livekit_service_url": "https://...",
    "allowed-identities": {
      "my-fancy-video-bot": "<some name here>"
    }
  }
}

maybe the name can also be taken from the livekit participant via the livekit js sdk, and the allowed-identities value can just be an array.