feat(crafting): add monster drops

feat(crafting): add monster drops

We now have per-monster drop tables that link back to items (Airtable).

It allows us to select an item + monster, and set a drop rate for that item,
as well as a min/max quantity. When the monster is killed, we use the drop table
to determine how many of that item to drop.

That item gets added to the players Items inventory.

In order to support the fact that crafting isn't in play yet, if an item
doesn't have an effect_name, we disable the "use" button.

Eventually these crafting items will be only usable through the crafting
system to improve your existing weapons/armour