Loki: Set Query limits context header (#114112)

* feat(lokiQueryLimitsContext): send full query range & expr on initial split requests

pkg/services/featuremgmt/registry.go

@@ -983,7 +983,7 @@ var (
 		},
 		{
 			Name:         "exploreLogsShardSplitting",
-			Description:  "Used in Logs Drilldown to split queries into multiple queries based on the number of shards",
+			Description:  "Deprecated. Replace with lokiShardSplitting. Used in Logs Drilldown to split queries into multiple queries based on the number of shards",
 			Stage:        FeatureStageExperimental,
 			FrontendOnly: true,
 			Owner:        grafanaObservabilityLogsSquad,
@@ -1938,6 +1938,13 @@ var (
 			FrontendOnly: true,
 			Owner:        grafanaPluginsPlatformSquad,
 		},
+		{
+			Name:         "lokiQueryLimitsContext",
+			Description:  "Send X-Loki-Query-Limits-Context header to Loki on first split request",
+			Stage:        FeatureStageExperimental,
+			FrontendOnly: true,
+			Owner:        grafanaObservabilityLogsSquad,
+		},
 		{
 			Name:            "rudderstackUpgrade",
 			Description:     "Enables the new version of rudderstack",

pkg/services/featuremgmt/toggles_gen.csv

@@ -263,4 +263,5 @@ kubernetesAnnotations,experimental,@grafana/grafana-backend-services-squad,false
 awsDatasourcesHttpProxy,experimental,@grafana/aws-datasources,false,false,false
 transformationsEmptyPlaceholder,preview,@grafana/datapro,false,false,true
 ttlPluginInstanceManager,experimental,@grafana/plugins-platform-backend,false,false,true
+lokiQueryLimitsContext,experimental,@grafana/observability-logs,false,false,true
 rudderstackUpgrade,experimental,@grafana/grafana-frontend-platform,false,false,true