The right to remain silent is in criminal proceedings.
Your half googled, half made up rubbish isn’t factual I’m afraid.
Ejecting someone for breach of a contract condition is merely removing their licence to remain.
Not arrest in any way. There is no right to breach a condition which affirms you must prove your right to a concession. You can keep silent but it’s not under the right to remain silent, it’s just because you choose to breach.
Once you work out this is civil law, contract and tort... not legislation breaches... you may get this.
Stewards arresting people is no different to you or I arresting someone. The public have limited powers dependant on suspicion levels and gravity of offence. It’s nothing to do with concessions and ID.