[ES|QL] Map Completion logical plan to ConpletionExec physical plan.

Author: afoucret

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/planner/mapper/MapperUtils.java

@@ -26,6 +26,7 @@
 import org.elasticsearch.xpack.esql.plan.logical.RrfScoreEval;
 import org.elasticsearch.xpack.esql.plan.logical.TimeSeriesAggregate;
 import org.elasticsearch.xpack.esql.plan.logical.UnaryPlan;
+import org.elasticsearch.xpack.esql.plan.logical.inference.Completion;
 import org.elasticsearch.xpack.esql.plan.logical.inference.Rerank;
 import org.elasticsearch.xpack.esql.plan.logical.local.LocalRelation;
 import org.elasticsearch.xpack.esql.plan.logical.show.ShowInfo;
@@ -43,6 +44,7 @@
 import org.elasticsearch.xpack.esql.plan.physical.RrfScoreEvalExec;
 import org.elasticsearch.xpack.esql.plan.physical.ShowExec;
 import org.elasticsearch.xpack.esql.plan.physical.TimeSeriesAggregateExec;
+import org.elasticsearch.xpack.esql.plan.physical.inference.CompletionExec;
 import org.elasticsearch.xpack.esql.plan.physical.inference.RerankExec;
 import org.elasticsearch.xpack.esql.planner.AbstractPhysicalOperationProviders;
 
@@ -99,6 +101,10 @@ static PhysicalPlan mapUnary(UnaryPlan p, PhysicalPlan child) {
             );
         }
 
+        if (p instanceof Completion completion) {
+            return new CompletionExec(completion.source(), child, completion.inferenceId(), completion.prompt(), completion.targetField());
+        }
+
         if (p instanceof Enrich enrich) {
             return new EnrichExec(
                 enrich.source(),