right-size 14 services and scale down GPU-heavy workloads [ci skip]

Memory right-sizing based on VPA upperBound analysis:
- Increases: stirling-pdf 1200→1536Mi, claude-memory 64→128Mi,
  dawarich 512→768Mi, kyverno-cleanup 128→192Mi, linkwarden 768→1Gi,
  navidrome 64→128Mi, listenarr 768→896Mi, privatebin 64→128Mi,
  ntfy 64→128Mi, health 128→256Mi, dbaas quota 16→20Gi,
  mysql-operator 384→512Mi
- Decreases: rybbit 768→384Mi, nvidia-exporter added explicit 192Mi,
  dcgm-exporter 2560→1536Mi
- Scale to 0: ebook2audiobook/audiblez-web, whisper (GPU node pressure)

Net effect: -496Mi cluster-wide, 13 ContainerNearOOM alerts resolved,
all ResourceQuota pressures cleared, GPU health green.

stacks/platform/modules/dbaas/main.tf

@@ -35,8 +35,8 @@ resource "kubernetes_resource_quota" "dbaas" {
   spec {
     hard = {
       "requests.cpu"    = "8"
-      "requests.memory" = "16Gi"
-      "limits.memory"   = "16Gi"
+      "requests.memory" = "20Gi"
+      "limits.memory"   = "20Gi"
       pods              = "30"
     }
   }
@@ -78,10 +78,10 @@ resource "helm_release" "mysql_operator" {
     resources = {
       requests = {
         cpu    = "100m"
-        memory = "384Mi"
+        memory = "512Mi"
       }
       limits = {
-        memory = "384Mi"
+        memory = "512Mi"
       }
     }
   })]