Schema: convert dashboards from v1beta1 to v2beta1 (#109037)

- Implement full conversion pipeline from v1beta1 → v2beta1
- Ensure frontend–backend parity for all dashboard serialization paths
- Add automatic data loss detection for conversions (panels, queries, annotations, links, variables)
- Extract atomic conversion functions for v0 → v1beta1 → v2alpha1 → v2beta1
- Introduce conversion metrics and detailed logging for loss tracking
- Normalize datasource resolution, defaults, and annotation processing
- Improve panel layout serialization and y-coordinate normalization
- Fix inconsistencies in nested panels and collapsed row behavior
- Refine variable handling:
  - Filter refId from variable query specs
  - Default variable refresh to 'never' (matches frontend)
  - Fix constant and interval variable handling for missing queries
- Unify schema defaults (enable, hide, iconColor, editable, liveNow)
- Fix pluginId usage (UID vs type) and datasource references
- Fix metrics.go bug swallowing errors (return nil → return err)
- Add tests for version-specific conversion error handling
- Add data loss detection tests using source/target version comparison
- Clean up lint issues, legacy code, and redundant files
- Update OpenAPI snapshots and migrated dashboards
- Improve backend migrator to reuse datasource provider and match frontend logic

Co-authored-by: Haris Rozajac <haris.rozajac12@gmail.com>
Co-authored-by: Oscar Kilhed <oscar.kilhed@grafana.com>
Co-authored-by: Stephanie Hingtgen <stephanie.hingtgen@grafana.com>

apps/dashboard/pkg/migration/testdata/input/v11.no-op-migration.json

@@ -40,13 +40,7 @@
       ]
     },
     "annotations": {
-      "list": [
-        {
-          "name": "Annotations & Alerts",
-          "datasource": "grafana",
-          "enable": true
-        }
-      ]
+      "list": []
     },
     "time": {
       "from": "now-6h",

apps/dashboard/pkg/migration/testdata/input/v15.no-op-migration.json

@@ -43,7 +43,10 @@
       "list": [
         {
           "name": "Annotations & Alerts",
-          "datasource": "grafana",
+          "datasource": {
+            "type": "grafana",
+            "uid": "grafana"
+          },
           "enable": true
         }
       ]

apps/dashboard/pkg/migration/testdata/input/v34.multiple_stats_cloudwatch.json

@@ -110,7 +110,9 @@
         "enable": true,
         "iconColor": "purple",
         "datasource": {
-          "uid": "prometheus"
+          "uid": "default-ds-uid",
+          "type": "prometheus",
+          "apiVersion": "v1"
         }
       }
     ]

apps/dashboard/pkg/migration/testdata/input/v36.ds_name_to_ref.json

@@ -34,6 +34,8 @@
       {
         "name": "Unknown Datasource Annotation - Tests unknown datasource preserved as UID",
         "datasource": {
+          "type": "prometheus",
+          "apiVersion": "v1",
           "uid": "unknown-datasource-name"
         }
       }
@@ -119,7 +121,9 @@
         {
           "refId": "B",
           "datasource": {
-            "uid": "existing-target-uid"
+            "uid": "existing-target-uid",
+            "type": "elasticsearch",
+            "apiVersion": "v2"
           }
         }
       ]
@@ -137,7 +141,8 @@
           "refId": "A",
           "datasource": {
             "uid": "existing-target-uid",
-            "type": "elasticsearch"
+            "type": "elasticsearch",
+            "apiVersion": "v2"
           }
         }
       ]
@@ -167,7 +172,9 @@
         {
           "refId": "A",
           "datasource": {
-            "uid": "existing-target-uid"
+            "uid": "existing-target-uid",
+            "type": "elasticsearch",
+            "apiVersion": "v2"
           }
         },
         {
@@ -188,7 +195,9 @@
         {
           "refId": "A",
           "datasource": {
-            "uid": "existing-target-uid"
+            "uid": "existing-target-uid",
+            "type": "elasticsearch",
+            "apiVersion": "v2"
           }
         }
       ]
@@ -257,7 +266,9 @@
             {
               "refId": "A",
               "datasource": {
-                "uid": "existing-target-uid"
+                "uid": "existing-target-uid",
+                "type": "elasticsearch",
+                "apiVersion": "v2"
               }
             }
           ]

apps/dashboard/pkg/migration/testdata/input/v42.harky_must.json

@@ -0,0 +1,31 @@
+{
+    "title": "v42 Migration Test - Harky Must",
+    "schemaVersion": 41,
+    "panels": [
+      {
+        "id": 1,
+        "title": "Panel with hideFrom.viz = true",
+        "type": "timeseries",
+        "fieldConfig": {
+          "defaults": {},
+          "overrides": [
+            {
+              "matcher": {
+                "id": "byName",
+                "options": "Field1"
+              },
+              "properties": [
+                {
+                  "id": "custom.hideFrom",
+                  "value": {
+                    "viz": true
+                  }
+                }
+              ]
+            }
+          ]
+        }
+      }
+    ]
+  }
+  

apps/dashboard/pkg/migration/testdata/input/v42.hidefrom_tooltip.json

@@ -49,14 +49,22 @@
             ]
           },
           {
+            "__systemRef": "hideSeriesFrom",
             "matcher": {
-              "id": "__systemRef",
-              "options": "hiddenSeries"
+              "id": "byNames",
+              "options": {
+                "mode": "exclude",
+                "names": ["foo"],
+                "prefix": "All except:",
+                "readOnly": true
+              }
             },
             "properties": [
               {
                 "id": "custom.hideFrom",
                 "value": {
+                  "legend": false,
+                  "tooltip": false,
                   "viz": true
                 }
               }
@@ -103,6 +111,10 @@
             "defaults": {},
             "overrides": [
               {
+                "matcher": {
+                  "id": "byName",
+                  "options": "Time"
+                },
                 "properties": [
                   {
                     "id": "unit",
@@ -123,13 +135,18 @@
         "defaults": {},
         "overrides": [
           {
+            "matcher": {
+              "id": "byValue",
+              "options": {
+                "op": "gte",
+                "reducer": "allIsZero",
+                "value": 0
+              }
+            },
             "properties": [
               {
-                "id": "custom.hideFrom",
-                "value": {
-                  "viz": false,
-                  "tooltip": false
-                }
+                "id": "unit",
+                "value": "short"
               }
             ]
           }
@@ -144,12 +161,17 @@
         "defaults": {},
         "overrides": [
           {
+            "matcher": {
+              "id": "byName",
+              "options": "{__name__=\"ALERTS\", alertname=\"k6CloudServiceErrorsLogged\"}"
+            },
             "properties": [
               {
                 "id": "custom.hideFrom",
                 "value": {
-                  "viz": true,
-                  "tooltip": false
+                  "legend": false,
+                  "tooltip": false,
+                  "viz": true
                 }
               }
             ]

apps/dashboard/pkg/migration/testdata/input/v6.pulldowns_and_templating.json

@@ -12,14 +12,20 @@
       "annotations": [
         {
           "name": "deployment",
-          "datasource": "prometheus",
+          "datasource": {
+            "uid": "default-ds-uid",
+            "type": "prometheus"
+          },
           "enable": true,
           "iconColor": "red",
           "query": "ALERTS{alertname=\"DeploymentStarted\"}"
         },
         {
           "name": "alerts",
-          "datasource": "loki",
+          "datasource": {
+            "uid": "loki-uid",
+            "type": "loki"
+          },
           "enable": false,
           "iconColor": "yellow",
           "query": "{job=\"alertmanager\"}"
@@ -32,12 +38,14 @@
       {
         "name": "environment",
         "type": "filter",
-        "allFormat": null
+        "allFormat": null,
+        "query": "label_values(up, instance)"
       },
       {
         "name": "service",
         "datasource": "prometheus",
-        "allFormat": "glob"
+        "allFormat": "glob",
+        "query": "label_values(up, instance)"
       },
       {
         "name": "region",