Raise puppet-postgres memory (#566)

The puppet-postgres primary is repeatedly OOMKilled at its 512Mi limit, causing repeated failovers; one left a replica diverged and serving stale PuppetDB reads.

- raise memory request 256Mi -> 1Gi and limit 512Mi -> 2Gi
- raise shared_buffers 128MB -> 256MB
- raise effective_cache_size 256MB -> 1GB

Reviewed-on: #566
Co-authored-by: unkin-agent <unkin-agent@unkin.net>
Co-committed-by: unkin-agent <unkin-agent@unkin.net>

apps/base/puppet/cnpg_cluster.yaml

@@ -85,7 +85,7 @@ spec:
       archive_mode: "on"
       archive_timeout: 5min
       dynamic_shared_memory_type: posix
-      effective_cache_size: 256MB
+      effective_cache_size: 1GB
       full_page_writes: "on"
       log_destination: csvlog
       log_directory: /controller/log
@@ -98,7 +98,7 @@ spec:
       max_parallel_workers: "16"
       max_replication_slots: "16"
       max_worker_processes: "16"
-      shared_buffers: 128MB
+      shared_buffers: 256MB
       shared_memory_type: mmap
       ssl_max_protocol_version: TLSv1.3
       ssl_min_protocol_version: TLSv1.3
@@ -127,10 +127,10 @@ spec:
   resources:
     limits:
       cpu: 500m
-      memory: 512Mi
+      memory: 2Gi
     requests:
       cpu: 50m
-      memory: 256Mi
+      memory: 1Gi
   smartShutdownTimeout: 180
   startDelay: 3600
   stopDelay: 1800