[TheSilentPro]

Summary

Implements #99 by displaying the effective economy price directly in purchasable head lore without modifying the canonical item that is given to players.

Behavior

• adds a configurable texts.head-price-lore template in gui.yml;
• displays the effective formatted Vault price for priced heads in search/category results, favorites, custom heads/player heads, and custom category views;
• omits the price line when economy is unavailable/disabled or the effective price is free;
• honors the existing price precedence (per-head → custom category when applicable → player-head/category → fallback);
• recreates fresh canonical items when purchasing from legacy GUI lists so GUI-only price/favorite/admin lore never leaks onto delivered heads;
• ensures custom-category views display and charge the same custom-category price.

Default template:

texts:
  head-price-lore: '<gray>Price: <gold>%price%'

Existing gui.yml files receive the missing default automatically through the existing GUI config merge behavior.