Revert "feat: auto select medals and make badges interactive"

This reverts commit 4516f77727.

backend/src/main/java/com/openisle/service/MedalService.java

@@ -83,17 +83,6 @@ public class MedalService {
         seedUserMedal.setSelected(selected == MedalType.SEED);
         medals.add(seedUserMedal);
 
-        if (user != null && medals.stream().noneMatch(MedalDto::isSelected)) {
-            medals.stream()
-                    .filter(MedalDto::isCompleted)
-                    .findFirst()
-                    .ifPresent(m -> {
-                        m.setSelected(true);
-                        user.setDisplayMedal(m.getType());
-                        userRepository.save(user);
-                    });
-        }
-
         return medals;
     }