refactor: eliminar código muerto (constantes legacy y métodos sin usar)

- defines.hpp: eliminar WINDOW_ZOOM_MIN, WINDOW_ZOOM_MAX (legacy),
  ROTOBALL_TRANSITION_TIME y LOGO_MODE_MIN_BALLS (reemplazada por
  LOGO_MIN_SCENARIO_IDX)
- resource_pack: eliminar encryptData/decryptData (XOR preparado pero
  nunca integrado en el pipeline de carga/guardado)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

source/resource_pack.cpp

@@ -231,17 +231,6 @@ void ResourcePack::clear() {
 // FUNCIONES AUXILIARES
 // ============================================================================
 
-void ResourcePack::encryptData(unsigned char* data, size_t size) {
-    for (size_t i = 0; i < size; i++) {
-        data[i] ^= XOR_KEY;
-    }
-}
-
-void ResourcePack::decryptData(unsigned char* data, size_t size) {
-    // XOR es simétrico
-    encryptData(data, size);
-}
-
 uint32_t ResourcePack::calculateChecksum(const unsigned char* data, size_t size) {
     uint32_t checksum = 0;
     for (size_t i = 0; i < size; i++) {