Fix/exception mapper (#3083)

* Added mapping for OptimisticLockingFailureException in ExceptionMapper for proper propagation

Signed-off-by: vasilchev <vasil.ilchev@bosch.com>

* Added ExceptionMapperTest

Signed-off-by: vasilchev <vasil.ilchev@bosch.com>

---------

Signed-off-by: vasilchev <vasil.ilchev@bosch.com>

hawkbit-repository/hawkbit-repository-api/src/main/java/org/eclipse/hawkbit/repository/exception/ConcurrentModificationException.java

@@ -0,0 +1,32 @@
+/**
+ * Copyright (c) 2026 Contributors to the Eclipse Foundation
+ *
+ * This program and the accompanying materials are made
+ * available under the terms of the Eclipse Public License 2.0
+ * which is available at https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package org.eclipse.hawkbit.repository.exception;
+
+import java.io.Serial;
+
+import lombok.EqualsAndHashCode;
+import lombok.ToString;
+import org.eclipse.hawkbit.exception.AbstractServerRtException;
+import org.eclipse.hawkbit.exception.SpServerError;
+
+/**
+ * Thrown when an entity cannot be stored because it was modified concurrently in another session (optimistic locking conflict).
+ */
+@EqualsAndHashCode(callSuper = true)
+@ToString(callSuper = true)
+public class ConcurrentModificationException extends AbstractServerRtException {
+
+    @Serial
+    private static final long serialVersionUID = 1L;
+
+    public ConcurrentModificationException(final Throwable cause) {
+        super(SpServerError.SP_REPO_CONCURRENT_MODIFICATION, cause);
+    }
+}