Conjured items degrade twice as fast as normal ones. Matched by name
prefix so any "Conjured ..." item works, not just the Mana Cake.
Wrote the tests first, then the updater. Only the Mana Cake lines
changed in the approved output.
ItemUpdater has the normal rules. Brie, backstage passes and Sulfuras
subclass it and override only what differs. GildedRose picks the right
one through updater_for. Tests and approved output unchanged.
No behaviour change. Named the item strings and the 0/50 bounds, moved
the body into _update_item and return early for Sulfuras so the rest of
the ladder only deals with items that actually change.
uzairarslan