Classic Armor&Stuff

Refined armor shield and HUD behavior.

- Added Shift override for AOE tools: holding Shift now disables AOE mining and performs normal single-block mining.
- Fixed tool and weapon HUD opacity behavior so 0% opacity stays fully opaque, while configured fade affects both the HUD background and text.
- Reduced false armor equip sounds by avoiding redundant shield NBT writes and only firing armor equip callbacks when the equipped item actually changes.
- Reworked shield entropy recovery to better match 1.12.2 behavior: entropy recovers after the hurt invulnerability window, and shield recharge stops at 100% entropy.
- Added Draconic armor Last Stand behavior for fatal damage prevention using remaining shield or armor energy.
- Restored dynamic shield-hit sound pitch based on remaining shield ratio, following the 1.12.2 formula.
- Added localized shield depleted messages.