refactor(telemetry): default the $service_name dashboard filter to 'xrpld'

Change the pre-selected value of the service_name template variable from
'All' to 'xrpld'. On first load, dashboards now filter to service.name=xrpld
directly rather than showing every service the collector sees. The 'All'
option is still selectable — this only changes the default the widget
starts on.

Reduces the chance of a fresh dashboard link showing unrelated services
(e.g. non-xrpld exporters sharing the same Grafana Cloud stack) before
the user narrows the filter.

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

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

@@ -984,8 +984,8 @@
         "includeAll": true,
         "allValue": ".*",
         "current": {
-          "text": "All",
+          "text": "xrpld",
-          "value": "$__all"
+          "value": "xrpld"
         },
         "multi": true,
         "refresh": 2,

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

@@ -335,8 +335,8 @@
         "includeAll": true,
         "allValue": ".*",
         "current": {
-          "text": "All",
+          "text": "xrpld",
-          "value": "$__all"
+          "value": "xrpld"
         },
         "multi": true,
         "refresh": 2,

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

@@ -169,8 +169,8 @@
         "includeAll": true,
         "allValue": ".*",
         "current": {
-          "text": "All",
+          "text": "xrpld",
-          "value": "$__all"
+          "value": "xrpld"
         },
         "multi": true,
         "refresh": 2,

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

@@ -434,8 +434,8 @@
         "includeAll": true,
         "allValue": ".*",
         "current": {
-          "text": "All",
+          "text": "xrpld",
-          "value": "$__all"
+          "value": "xrpld"
         },
         "multi": true,
         "refresh": 2,

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

@@ -864,8 +864,8 @@
         "includeAll": true,
         "allValue": ".*",
         "current": {
-          "text": "All",
+          "text": "xrpld",
-          "value": "$__all"
+          "value": "xrpld"
         },
         "multi": true,
         "refresh": 2,