Video playback on mobile doesn't work on self-hosted instance that enforces TLS 1.3

When attempting to play a video on our self-hosted instance on the mobile client (and only the mobile client), it instead displays an error message saying "Could not play this video." Our self-hosted instance was behind a reverse proxy that was configured to enforce TLS 1.3, i.e. reject connections using TLS 1.2 and lower. The fullscreen media player used on mobile (at least on Android) can't connect to this, though the rest of the app can. Relaxing the restriction to TLS 1.2 fixed the issue, though we also weren't able to enforce known good algorithms under TLS 1.2. Fluxer uses media-kit for its mobile video player, which uses libmpv v0.37.0 (or possibly older), which statically links libffmpeg, which is what actually downloads the video. To do so, ffmpeg statically links libmbedtls (a TLS library). So the network stack for the video player is actually completely isolated from the rest of the app, and also at least 3 years out of date. There's also an open issue on media-kit's GitHub for this: https://github.com/media-kit/media-kit/issues/1437 While it'd be nice to support modern TLS throughout the whole app, I can see there's multiple dependencies involved here. Therefore, in the short term, it might be nice to at least document this limitation somewhere. Although maybe this issue counts as documentation :)