What Hinge Should I Use For Heavy Swinging Shoe Cupboard?
Websearch will find good descriptions of bookcase secret doors using center pivot hinges, which are one of the best solutions currently available. If you were putting two cases next to each other, there are other solutions; the Rockler catalog (among others) offers one such center-fold bookcase door hardware kit. There are also companies who install these professionally.

Note that any pivoting case needs some clearance designed into the system. There are ways to mask that with additional moving pieces.

(Yes, I have plans to do something along these lines. Not sure I wsnt to say too much morel that risks taking the fun out of it.)