if a new recipe gets added to a book (because it was missing)
how do we add that new recipe to the player

i would think it would be added at character login when recipes books are read in ( but guess not)

If I remember right when you "use" a recipe book all the recipes are added to a table for the character. We also have a recipe_books table for the character so it may be possible to rework it so the recipes are pulled from the book instead of storing them in their own table.