refactor(telemetry): rename dashboard template variable label from 'Service' to 'Service Name'

The template variable's Prometheus label name is `service_name` but the
UI display label read 'Service', which mismatched what users typed into
Grafana's Metrics Drilldown UI (which defaults to filter on a bare
`service` label). Rename the display label to 'Service Name' so it
unambiguously points at the underlying `service_name` Prometheus label.

Behaviour unchanged; template-variable name (`service_name`) and PromQL
label are the same. Only the widget label shown at the top of the
dashboard changes from 'Service' to 'Service Name'.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

docker/telemetry/grafana/dashboards/consensus-health.json

@@ -973,7 +973,7 @@
     "list": [
       {
         "name": "service_name",
-        "label": "Service",
+        "label": "Service Name",
         "description": "Filter by service.name (e.g. xrpld, xrpld-validator)",
         "type": "query",
         "query": "label_values(service_name)",

docker/telemetry/grafana/dashboards/ledger-operations.json

@@ -324,7 +324,7 @@
     "list": [
       {
         "name": "service_name",
-        "label": "Service",
+        "label": "Service Name",
         "description": "Filter by service.name (e.g. xrpld, xrpld-validator)",
         "type": "query",
         "query": "label_values(service_name)",

docker/telemetry/grafana/dashboards/peer-network.json

@@ -158,7 +158,7 @@
     "list": [
       {
         "name": "service_name",
-        "label": "Service",
+        "label": "Service Name",
         "description": "Filter by service.name (e.g. xrpld, xrpld-validator)",
         "type": "query",
         "query": "label_values(service_name)",

docker/telemetry/grafana/dashboards/rpc-performance.json

@@ -423,7 +423,7 @@
     "list": [
       {
         "name": "service_name",
-        "label": "Service",
+        "label": "Service Name",
         "description": "Filter by service.name (e.g. xrpld, xrpld-validator)",
         "type": "query",
         "query": "label_values(service_name)",

docker/telemetry/grafana/dashboards/transaction-overview.json

@@ -853,7 +853,7 @@
     "list": [
       {
         "name": "service_name",
-        "label": "Service",
+        "label": "Service Name",
         "description": "Filter by service.name (e.g. xrpld, xrpld-validator)",
         "type": "query",
         "query": "label_values(service_name)",