style(opensearchtransport): name all OperationID String labels as constants

Replace the String() switch's string literals with a complete opName*
constant registry, and reference the constants from the discovery-flag
map and internal tests. One declaration per wire token; adding an
operation follows a fixed pattern and tooling can trace every use.

Signed-off-by: Sean Chittenden <sean.chittenden@crowdstrike.com>

Author: sean-

opensearchtransport/feature_config.go

@@ -173,9 +173,9 @@ func (f discoveryFeatures) nodeStatsEnabled() bool {
 //
 //nolint:gochecknoglobals // Package-level constant map for config parsing.
 var discoveryFlagNames = map[string]discoveryFeatures{
-	"cat_shards":         discoverySkipCatShards,
+	opNameCatShards:      discoverySkipCatShards,
 	"routing_num_shards": discoverySkipRoutingNumShards,
-	clusterHealthName:    discoverySkipClusterHealth,
+	opNameClusterHealth:  discoverySkipClusterHealth,
 	"node_stats":         discoverySkipNodeStats,
 }
 

opensearchtransport/observer_response_internal_test.go

@@ -182,7 +182,7 @@ func TestRequestEventIdentityFields(t *testing.T) {
 			name:          "system endpoint has empty index",
 			method:        http.MethodGet,
 			path:          "/_cluster/health",
-			wantRouteName: clusterHealthName,
+			wantRouteName: opNameClusterHealth,
 			wantIndex:     "",
 			wantPath:      "/_cluster/health",
 		},