Fix missing CMAB bucketing reasons in decision process

Added merge of bucketing reasons for CMAB experiments to ensure traffic allocation information is included in decision responses.

Co-authored-by: Mat001 <1386553+Mat001@users.noreply.github.com>

Author: Copilot

core-api/src/main/java/com/optimizely/ab/bucketing/DecisionService.java

@@ -173,7 +173,8 @@ public DecisionResponse<Variation> getVariation(@Nonnull Experiment experiment,
             decisionVariation = bucketer.bucket(experiment, bucketingId, projectConfig, decisionPath);
             if (decisionPath == DecisionPath.WITH_CMAB && isCmabExperiment(experiment) && decisionVariation.getResult() != null) {
                 // group-allocation and traffic-allocation checking passed for cmab  
-                // we need server decision overruling local bucketing for cmab  
+                // we need server decision overruling local bucketing for cmab
+                reasons.merge(decisionVariation.getReasons());
                 DecisionResponse<CmabDecision> cmabDecision = getDecisionForCmabExperiment(projectConfig, experiment, user, bucketingId, options);
                 reasons.merge(cmabDecision.getReasons());