Shield mechanics - Enhanced Shield Mechanics

Shields now have two important characteristics:
Main Shield Characteristics
Each shield now possesses two types of protection:
- Damage reduction when blocking: When actively blocking, the shield absorbs the specified percentage of damage
- Passive protection: Even just holding the shield in the off-hand gives you constant damage reduction
Different types of shields will have varying values for both active and passive protection, making shield choice a strategically important decision.
New Shield Enchantments
The mod adds 5 unique enchantments specifically designed for shields:
- Blocking: Increases blocking effectiveness by 10%
- Last Resort: Chance to gain absorption hearts when blocking at low health
- Blindness: Chance to blind attackers when successfully blocking
- Knockback: Probability to knock enemies back when blocking their attacks
- Slowness: Chance to slow down opponents when blocking their strikes

Parameter Configuration
All shield characteristics can be configured through the configuration file:
- Setting damage reduction when blocking
- Setting passive damage reduction
- Setting cooldown time after blocking
Shields that don't have custom settings automatically receive default values based on their durability.
This modification completely changes shield mechanics, so it pairs excellently with other mods that add new shield types to the game.

