fix cluster health: pin actualbudget, spread MySQL, scale grampsweb, fix GPU toleration

- Pin actualbudget/actual-server from edge to 26.3.0 (all 3 instances) to
  prevent recurring migration breakage from rolling nightly builds
- Add podAntiAffinity to MySQL InnoDB Cluster to spread replicas across nodes,
  relieving memory pressure on k8s-node4
- Scale grampsweb to 0 replicas (unused, consuming 1.7Gi memory)
- Add GPU toleration Kyverno policy to Terraform using patchesJson6902 instead
  of patchStrategicMerge to fix toleration array being overwritten (caused
  caretta DaemonSet pod to be unable to schedule on k8s-master)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

stacks/platform/modules/dbaas/main.tf

@@ -13,7 +13,7 @@ variable "prod" {
 }
 variable "nfs_server" { type = string }
 variable "kube_config_path" {
-  type = string
+  type      = string
   sensitive = true
 }
 
@@ -193,11 +193,21 @@ resource "helm_release" "mysql_cluster" {
               matchExpressions = [{
                 key      = "kubernetes.io/hostname"
                 operator = "NotIn"
-                values   = ["k8s-node2"]
+                values   = ["k8s-node1", "k8s-node2"]
               }]
             }]
           }
         }
+        podAntiAffinity = {
+          requiredDuringSchedulingIgnoredDuringExecution = [{
+            labelSelector = {
+              matchLabels = {
+                "component" = "mysqld"
+              }
+            }
+            topologyKey = "kubernetes.io/hostname"
+          }]
+        }
       }
       containers = [{
         name = "mysql"