THE RED CARPET THERE are moments of great luxury in the life of a secret agent. There are assignments on which he is required to act the part of a very rich man; occasions when he takes refuge in good living to efface the memory of danger and the shadow of death; and times when, as was now the case, he is a guest in the territory of an allied Secret Service. From the moment the BOAC Stratocruiser taxied up to the International Air Terminal at Idlewild, James Bond was treated like royalty. When he left the aircraft with the other passengers he had resigned himself to the notorious purgatory of the US Health, Immigration