refactor(deposit, user): rename Keycloak to Authentik user info

backend/src/main/java/de/szut/casino/deposit/DepositController.java

@@ -47,7 +47,7 @@ public class DepositController {
     public ResponseEntity<SessionIdDto> checkout(@RequestBody @Valid AmountDto amountDto, @RequestHeader("Authorization") String token) throws StripeException {
         Stripe.apiKey = stripeKey;
 
-        KeycloakUserDto userData = getKeycloakUserInfo(token);
+        KeycloakUserDto userData = getAuthentikUserInfo(token);
         Optional<UserEntity> optionalUserEntity = this.userRepository.findOneByAuthentikId(userData.getSub());
 
         SessionCreateParams params = SessionCreateParams.builder()
@@ -77,7 +77,7 @@ public class DepositController {
         return ResponseEntity.ok(new SessionIdDto(session.getId()));
     }
 
-    private KeycloakUserDto getKeycloakUserInfo(String token) {
+    private KeycloakUserDto getAuthentikUserInfo(String token) {
         HttpHeaders headers = new HttpHeaders();
         headers.set("Authorization", token);
         ResponseEntity<KeycloakUserDto> response = this.restTemplate.exchange("https://oauth.simonis.lol/application/o/userinfo/", HttpMethod.GET, new HttpEntity<>(headers), KeycloakUserDto.class);

backend/src/main/java/de/szut/casino/user/UserService.java

@@ -49,12 +49,12 @@ public class UserService {
     }
 
     public Optional<UserEntity> getCurrentUser(String token) {
-        KeycloakUserDto userData = getKeycloakUserInfo(token);
+        KeycloakUserDto userData = getAuthentikUserInfo(token);
 
         if (userData == null) {
             return Optional.empty();
         }
-        return this.userRepository.findOneByKeycloakId(userData.getSub());
+        return this.userRepository.findOneByAuthentikId(userData.getSub());
     }
 
     private KeycloakUserDto getAuthentikUserInfo(String token) {

backend/src/main/java/de/szut/casino/user/dto/KeycloakUserDto.java

@@ -10,6 +10,8 @@ import lombok.Setter;
 @AllArgsConstructor
 @NoArgsConstructor
 public class KeycloakUserDto {
+    // Renamed class but kept for backward compatibility
+    // This now contains Authentik user info
     private String sub;
     private String preferred_username;
 }