feat: Grafana-Panel Planung nach Kategorie inkl. Kreditraten (A11-T3)

Neue Tabelle planning_monthly (Monatssummen je Kategorie aus wiederkehrenden
Posten, Einmalposten und allen Kreditraten), Service planning_chart mit
refresh_planning_chart (Advisory-Lock, komplette Neuschreibung), GUI-Hooks
in index/planung_page ueber _safe_refresh, neues Barchart-Panel im
Grafana-Dashboard (Panel 5).

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

finance/grafana/dashboards/finanzen.json

@@ -168,6 +168,28 @@
           "rawQuery": true
         }
       ]
+    },
+    {
+      "id": 5,
+      "type": "barchart",
+      "title": "Planung nach Kategorie",
+      "datasource": { "type": "postgres", "uid": "FinanzDB" },
+      "gridPos": { "h": 8, "w": 12, "x": 0, "y": 16 },
+      "fieldConfig": { "defaults": { "unit": "currencyEUR" }, "overrides": [] },
+      "options": {
+        "legend": { "displayMode": "list", "placement": "bottom" },
+        "stacking": "normal",
+        "xTickLabelRotation": 0
+      },
+      "targets": [
+        {
+          "refId": "A",
+          "datasource": { "type": "postgres", "uid": "FinanzDB" },
+          "format": "time_series",
+          "rawSql": "SELECT month AS time, category AS metric, total AS value FROM planning_monthly ORDER BY month",
+          "rawQuery": true
+        }
+      ]
     }
   ]
 }