I have never stayed CL at the YC, but I have at several of Disney's other Deluxe resorts and I can tell you that in the evening (from about 5-7pm) there are offerings in the lounge that are essentially appetizers. It is definitely not meant to suffice for dinner BUT I have made a light supper out of it many times at AKL (chicken satay, an African-inspired black bean salad, hummus and pita chips and several other yummy selections...) but not sure about YC. Hopefully someone else can help with that.
There is also wine and beer to enjoy and yes, all the offerings in the lounge are complimentary. This is a big part of the Club level experience and what you're paying for.
If it's in your budget, why not check it ut for one night?