fix: right-size service memory after PVE RAM upgrade (142→272GB)

- MySQL InnoDB: 2Gi/4Gi → 3Gi/6Gi (was at 97% of limit)
- Redis HAProxy: 16Mi/16Mi → 32Mi/64Mi (OOMKilled)
- Plotting-book: 64Mi/64Mi → 128Mi/256Mi (OOMKilled)
- Tandoor: 256Mi/256Mi → 384Mi/512Mi (60 OOM restarts), re-enabled
- Navidrome: 128Mi/128Mi → 256Mi/384Mi
- Matrix: add explicit 256Mi/512Mi resources
- Trading-bot workers: 64Mi/64Mi → 128Mi/256Mi, re-enabled
- Tier 3-edge defaults: 96Mi/192Mi → 128Mi/256Mi
- Fallback tier defaults: 128Mi/128Mi → 128Mi/192Mi, max 2→4Gi
- Mailserver: disable rspamd-redis, fix Roundcube IPv6/IMAP, bump dovecot connections

stacks/dbaas/modules/dbaas/main.tf

@@ -35,8 +35,8 @@ resource "kubernetes_resource_quota" "dbaas" {
   spec {
     hard = {
       "requests.cpu"    = "8"
-      "requests.memory" = "27Gi"
-      "limits.memory"   = "27Gi"
+      "requests.memory" = "32Gi"
+      "limits.memory"   = "32Gi"
       pods              = "30"
     }
   }
@@ -228,11 +228,11 @@ resource "helm_release" "mysql_cluster" {
         name = "mysql"
         resources = {
           requests = {
-            memory = "2Gi"
+            memory = "3Gi"
             cpu    = "250m"
           }
           limits = {
-            memory = "4Gi"
+            memory = "6Gi"
           }
         }
       }]