Self-host ReDoc

[ghost]

Currently, ReDoc is pulled from cdn.redoc.ly. We should self-host ReDoc to not leak user data.

[g0dfl3sh]

Hey there! I had a short look at this. Could we just pull redoc.standalone.js into our repo and embed it like we do for ./backend/internal/server/html.index and ./backend/internal/server/openapi.yml?
The only thing is that this adds maintenance overhead to keep up with the latest version of redoc.standalone.js, but we could add a GHA job to take care of that potentially.

[abstractionfactory]

@g0dfl3sh ideally, this would be done as part of the go generate command and it would also be uploaded via the same mechanism as the OpenAPI file.

[g0dfl3sh]

Thanks @abstractionfactory for the hint! Going to start looking into that.