Grafana: Payments dashboard log fix & fine tune

@jcalderone This is a JSON-blob-only diff for the "Payments" dashboard. It should fix the log panels, make a couple of things a little bit better and probably nothing worse.

---

• (tryfix) Switch to Loki datasource;
• Filter requests to metrics instead of all GET;
• Show the last week by default
• Show log times

Interesting and not quickly fixable as it looks like: the GET ... line comes after the result. We might be logging this wrong to begin with, but probably this is some next gen AI line ordering intelligence

Update: Later added:

• Turn on shared crosshair for this dashboard (we might want this on the other dashes too?)
• Semi-transparency for the two lastly edited panels, for the looks

nixos/modules/monitoring/server/grafana-dashboards/payments.json

@@ -1031,7 +1031,7 @@
     {
       "datasource": {
         "type": "loki",
-        "uid": "P8E80F9AEF21F6940"
+        "uid": "000000002"
       },
       "description": "Exercise in counting maybe interesting lines. This can be alerted on.",
       "fieldConfig": {
@@ -1107,10 +1107,9 @@
         {
           "datasource": {
             "type": "loki",
-            "uid": "P8E80F9AEF21F6940"
+            "uid": "000000002"
           },
-          "expr": "count_over_time({host=\"payments\",unit=\"zkapissuer.service\"} !~ \"200|GET|Accept\" [5m])",
-          "maxLines": 0,
+          "expr": "count_over_time({host=\"payments\",unit=\"zkapissuer.service\"} !~ \"200|/metrics|Accept\" [5m])",
           "refId": "A"
         }
       ],
@@ -1121,7 +1120,7 @@
     {
       "datasource": {
         "type": "loki",
-        "uid": "P8E80F9AEF21F6940"
+        "uid": "000000002"
       },
       "description": "Exercise in filtering the payment server logs.",
       "gridPos": {
@@ -1137,7 +1136,7 @@
         "prettifyLogMessage": false,
         "showCommonLabels": false,
         "showLabels": false,
-        "showTime": false,
+        "showTime": true,
         "sortOrder": "Descending",
         "wrapLogMessage": false
       },
@@ -1145,9 +1144,9 @@
         {
           "datasource": {
             "type": "loki",
-            "uid": "P8E80F9AEF21F6940"
+            "uid": "000000002"
           },
-          "expr": "{host=\"payments\",unit=\"zkapissuer.service\"} !~ \"200|GET|Accept\"",
+          "expr": "{host=\"payments\",unit=\"zkapissuer.service\"} !~ \"200|/metrics|Accept\"",
           "refId": "A"
         }
       ],
@@ -1163,7 +1162,7 @@
     "list": []
   },
   "time": {
-    "from": "now-3h",
+    "from": "now-7d",
     "to": "now"
   },
   "timepicker": {