fix(plotting-book): increase memory limits to resolve OOMKill crash loop

64Mi was insufficient — pod was OOMKilled on startup.
Increased to 128Mi request / 256Mi limit.

[ci skip]

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

stacks/plotting-book/main.tf

@@ -150,11 +150,11 @@ resource "kubernetes_deployment" "plotting-book" {
           }
           resources {
             requests = {
-              memory = "64Mi"
+              memory = "128Mi"
               cpu    = "10m"
             }
             limits = {
-              memory = "64Mi"
+              memory = "256Mi"
             }
           }
         }