equalize memory req=lim across 70+ containers using Prometheus 7d max data

After node2 OOM incident, right-size memory across the cluster by setting
requests=limits based on max_over_time(container_memory_working_set_bytes[7d])
with 1.3x headroom. Eliminates ~37Gi overcommit gap.

Categories:
- Safe equalization (50 containers): set req=lim where max7d well within target
- Limit increases (8 containers): raise limits for services spiking above current
- No Prometheus data (12 containers): conservatively set lim=req
- Exception: nextcloud keeps req=256Mi/lim=8Gi due to Apache memory spikes

Also increased dbaas namespace quota from 12Gi to 16Gi to accommodate mysql
4Gi limits across 3 replicas.

stacks/platform/modules/mailserver/main.tf

@@ -362,7 +362,7 @@ resource "kubernetes_deployment" "mailserver" {
           resources {
             requests = {
               cpu    = "25m"
-              memory = "128Mi"
+              memory = "512Mi"
             }
             limits = {
               memory = "512Mi"
@@ -391,10 +391,10 @@ resource "kubernetes_deployment" "mailserver" {
           resources {
             requests = {
               cpu    = "10m"
-              memory = "16Mi"
+              memory = "32Mi"
             }
             limits = {
-              memory = "64Mi"
+              memory = "32Mi"
             }
           }
         }

stacks/platform/modules/mailserver/roundcubemail.tf

@@ -155,6 +155,15 @@ resource "kubernetes_deployment" "roundcubemail" {
             name       = "enigma"
             mount_path = "/var/roundcube/enigma"
           }
+          resources {
+            requests = {
+              cpu    = "25m"
+              memory = "192Mi"
+            }
+            limits = {
+              memory = "192Mi"
+            }
+          }
         }
 
         # volume {