App 2.19.7: meter AC charging too, while the app runs

A session runs whenever power flows into the pack, AC or DC; gaps the
head unit slept through are dropped as before. Dashboard and server
texts no longer say DC only.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LhzAVaUyqcw5PkGjz4mWW6

k8s/grafana/dashboards/charging.json

@@ -1,7 +1,7 @@
 {
   "uid": "mg4-charging",
   "title": "MG4 - Charging",
-  "description": "DC charging sessions metered by the car. Prices in euro, as entered in the car's Charging tab.",
+  "description": "Charging sessions (AC and DC) metered by the car while its head unit was awake. Prices in euro, as entered in the car's Charging tab.",
   "tags": [
     "mg4"
   ],
@@ -43,7 +43,7 @@
     {
       "id": 1,
       "type": "stat",
-      "title": "DC sessions",
+      "title": "Charging sessions",
       "datasource": {
         "type": "influxdb",
         "uid": "mg4-influxdb"
@@ -511,7 +511,7 @@
           "mode": "multi"
         }
       },
-      "description": "Only DC charges above 10 kW are metered. Pick a time range around a session to see its curve."
+      "description": "AC and DC charges are metered while the head unit is awake; up to app 2.19.6 only DC above 10 kW was. Pick a time range around a session to see its curve."
     }
   ]
 }