swarm-grafana: add a subscription usage line to the claude usage dashboard

nix/host-modules/swarm-grafana/dashboards/claude-usage.json

@@ -992,6 +992,64 @@
           "values": false
         }
       }
+    },
+    {
+      "id": 44,
+      "type": "timeseries",
+      "title": "Subscription usage, highest window",
+      "description": "Highest subscription usage percent across all agents and windows.",
+      "datasource": {
+        "type": "prometheus",
+        "uid": "@datasourceUid@"
+      },
+      "gridPos": {
+        "h": 8,
+        "w": 24,
+        "x": 0,
+        "y": 39
+      },
+      "targets": [
+        {
+          "refId": "A",
+          "datasource": {
+            "type": "prometheus",
+            "uid": "@datasourceUid@"
+          },
+          "expr": "max({__name__=\"hyperhive.agent.claude_usage.percent\", hive=~\"$hive\", agent=~\"$agent\"})",
+          "legendFormat": "highest window"
+        }
+      ],
+      "fieldConfig": {
+        "defaults": {
+          "unit": "percent",
+          "min": 0,
+          "max": 100,
+          "color": {
+            "mode": "fixed",
+            "fixedColor": "orange"
+          },
+          "custom": {
+            "drawStyle": "line",
+            "lineWidth": 1,
+            "fillOpacity": 10,
+            "showPoints": "never",
+            "spanNulls": false
+          }
+        },
+        "overrides": []
+      },
+      "options": {
+        "legend": {
+          "displayMode": "list",
+          "placement": "bottom",
+          "showLegend": false,
+          "calcs": []
+        },
+        "tooltip": {
+          "mode": "single",
+          "sort": "none"
+        }
+      }
     }
   ]
 }