fix(immich): bump postgres memory 512Mi → 1Gi for v2.6.1 geodata migration

v2.6.1 bulk-inserts into geodata_places on first boot, OOM-killing
postgres at 512Mi. Raise to 1Gi to accommodate the migration.

stacks/immich/main.tf

@@ -431,10 +431,10 @@ resource "kubernetes_deployment" "immich-postgres" {
           resources {
             requests = {
               cpu    = "50m"
-              memory = "512Mi"
+              memory = "1Gi"
             }
             limits = {
-              memory = "512Mi"
+              memory = "1Gi"
             }
           }
         }