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/vault/main.tf

@@ -44,8 +44,8 @@ resource "helm_release" "vault" {
       enabled = true
 
       resources = {
-        requests = { memory = "128Mi", cpu = "100m" }
-        limits   = { memory = "512Mi" }
+        requests = { memory = "384Mi", cpu = "100m" }
+        limits   = { memory = "384Mi" }
       }
 
       # Allow scheduling on GPU node (node1)