Officially you are restricted to the hotel during the layover and require a "gate pass" to exit to town. However, only Skylight seemed to be enforcing this (and even then I'm not sure they are still doing so as I haven't stayed there since December). The current regulations for a gate pass require you to present any of the documents referred to above for entry (PCR, antigen, recovery or vaccination certs) or else to conduct a rapid antigen test at the hotel. In practice, you can probably just walk out without any issue and are unlikely to be stopped or questioned.