Add body type selection for nonbinary characters and reduce preview rotation sensitivity

Nonbinary characters can now choose between masculine and feminine body types in character creation, with real-time preview updates and full appearance customization. Body type preference is saved to character config and persists across sessions. Also reduces character preview drag-to-rotate sensitivity from 0.5 to 0.2 for better control.

include/rendering/character_preview.hpp

@@ -23,7 +23,7 @@ public:
     bool loadCharacter(game::Race race, game::Gender gender,
                        uint8_t skin, uint8_t face,
                        uint8_t hairStyle, uint8_t hairColor,
-                       uint8_t facialHair);
+                       uint8_t facialHair, bool useFemaleModel = false);
 
     void update(float deltaTime);
     void render();