Reconstruct Element

Added four new forging books, which can be found in chests and used to craft books of corresponding attributes.

Optimized attribute priority: items that have been modified by a forging book on an anvil always take priority > Impact > Pierce > Slash > Neutral.

Optimized attribute detection: an item can possess multiple attributes, but only one attribute will be recognized, based on the priority in point 2. An attribute the item does not possess cannot be applied or changed via a forging book on an anvil.
Example: an iron sword with both Impact and Slash is treated as Impact by default, and cannot be given Pierce via forging. It can, however, be switched to Slash, and switched back at any time. Applying a forging book of the same attribute to an item that already has that attribute is not allowed.

In-game attribute display (left side shows the recognized attribute, right side shows the possessed attributes).