ingress latency: add histogram buckets, fix restarts, right-size memory

- Traefik: add fine-grained Prometheus histogram buckets (0.01-30s) for meaningful P50/P99
- Calibre: relax liveness probe (timeout 5→10s, threshold 3→6) to stop NFS-caused restarts
- Novelapp: increase memory 128Mi/256Mi → 640Mi/640Mi (confirmed OOMKilled, VPA upper 505Mi)
- Forgejo: increase memory 256Mi → 384Mi (at 80% of limit, VPA upper 311Mi)
- ActualBudget: add explicit resources to prevent silent LimitRange defaults
- Docs: update Nextcloud note from 4Gi → 8Gi limit (Apache spike history)

stacks/actualbudget/factory/main.tf

@@ -64,6 +64,15 @@ resource "kubernetes_deployment" "actualbudget" {
           port {
             container_port = 5006
           }
+          resources {
+            requests = {
+              cpu    = "15m"
+              memory = "160Mi"
+            }
+            limits = {
+              memory = "256Mi"
+            }
+          }
           volume_mount {
             name       = "data"
             mount_path = "/data"