fix: handle url.full and http.url in third-party API endpoint count

Use two queries combined via formula to count distinct endpoints
across both semconv versions (url.full and http.url).
This avoids missing count for endpoint if only url.full is used.

Alternative a simple coalesce in count_distinct would have fixed
this but it would require substantial query builder refactoring
since it's not supported currently.

pkg/modules/thirdpartyapi/translator.go

@@ -81,8 +81,10 @@ func FilterIntermediateColumns(result *qbtypes.QueryRangeResponse) *qbtypes.Quer
 		// Filter out columns for intermediate queries used only in formulas
 		filteredColumns := make([]*qbtypes.ColumnDescriptor, 0)
 		intermediateQueryNames := map[string]bool{
-			"error":      true,
-			"total_span": true,
+			"error":             true,
+			"total_span":        true,
+			"endpoints_current": true,
+			"endpoints_legacy":  true,
 		}
 
 		columnIndices := make([]int, 0)
@@ -296,15 +298,15 @@ func BuildDomainList(req *thirdpartyapitypes.ThirdPartyApiRequest) (*qbtypes.Que
 		return nil, err
 	}
 
-	queries := []qbtypes.QueryEnvelope{
-		buildEndpointsQuery(req),
+	queries := buildEndpointsQueries(req)
+	queries = append(queries,
 		buildLastSeenQuery(req),
 		buildRpsQuery(req),
 		buildErrorQuery(req),
 		buildTotalSpanQuery(req),
 		buildP99Query(req),
 		buildErrorRateFormula(),
-	}
+	)
 
 	return &qbtypes.QueryRangeRequest{
 		SchemaVersion: "v5",
@@ -346,20 +348,58 @@ func BuildDomainInfo(req *thirdpartyapitypes.ThirdPartyApiRequest) (*qbtypes.Que
 	}, nil
 }
 
-func buildEndpointsQuery(req *thirdpartyapitypes.ThirdPartyApiRequest) qbtypes.QueryEnvelope {
-	return qbtypes.QueryEnvelope{
+// buildEndpointsQueries returns queries for counting distinct URLs with semconv fallback.
+// It uses two queries with mutually exclusive filters:
+// - endpoints_current: count_distinct(url.full) WHERE url.full EXISTS
+// - endpoints_legacy: count_distinct(http.url) WHERE url.full NOT EXISTS
+// And a formula to combine them: endpoints_current + endpoints_legacy
+func buildEndpointsQueries(req *thirdpartyapitypes.ThirdPartyApiRequest) []qbtypes.QueryEnvelope {
+	// Query for current semconv (url.full)
+	currentFilter := buildBaseFilter(req.Filter)
+	currentFilter.Expression = fmt.Sprintf("(%s) AND %s EXISTS", currentFilter.Expression, urlPathKey)
+
+	endpointsCurrent := qbtypes.QueryEnvelope{
 		Type: qbtypes.QueryTypeBuilder,
 		Spec: qbtypes.QueryBuilderQuery[qbtypes.TraceAggregation]{
-			Name:         "endpoints",
+			Name:         "endpoints_current",
 			Signal:       telemetrytypes.SignalTraces,
 			StepInterval: qbtypes.Step{Duration: defaultStepInterval},
 			Aggregations: []qbtypes.TraceAggregation{
-				{Expression: "count_distinct(http.url)"},
+				{Expression: fmt.Sprintf("count_distinct(%s)", urlPathKey)},
 			},
-			Filter:  buildBaseFilter(req.Filter),
+			Filter:  currentFilter,
 			GroupBy: mergeGroupBy(dualSemconvGroupByKeys["server"], req.GroupBy),
 		},
 	}
+
+	// Query for legacy semconv (http.url) - only when url.full doesn't exist
+	legacyFilter := buildBaseFilter(req.Filter)
+	legacyFilter.Expression = fmt.Sprintf("(%s) AND %s NOT EXISTS", legacyFilter.Expression, urlPathKey)
+
+	endpointsLegacy := qbtypes.QueryEnvelope{
+		Type: qbtypes.QueryTypeBuilder,
+		Spec: qbtypes.QueryBuilderQuery[qbtypes.TraceAggregation]{
+			Name:         "endpoints_legacy",
+			Signal:       telemetrytypes.SignalTraces,
+			StepInterval: qbtypes.Step{Duration: defaultStepInterval},
+			Aggregations: []qbtypes.TraceAggregation{
+				{Expression: fmt.Sprintf("count_distinct(%s)", urlPathKeyLegacy)},
+			},
+			Filter:  legacyFilter,
+			GroupBy: mergeGroupBy(dualSemconvGroupByKeys["server"], req.GroupBy),
+		},
+	}
+
+	// Formula to combine both counts
+	endpointsFormula := qbtypes.QueryEnvelope{
+		Type: qbtypes.QueryTypeFormula,
+		Spec: qbtypes.QueryBuilderFormula{
+			Name:       "endpoints",
+			Expression: "endpoints_current + endpoints_legacy",
+		},
+	}
+
+	return []qbtypes.QueryEnvelope{endpointsCurrent, endpointsLegacy, endpointsFormula}
 }
 
 func buildLastSeenQuery(req *thirdpartyapitypes.ThirdPartyApiRequest) qbtypes.QueryEnvelope {