reduce cnpg connections, but increase working memory

manifests/infrastructure/postgresql/cluster-shared.yaml

@@ -12,7 +12,7 @@ spec:
   
   # Use CloudNativePG-compatible PostGIS image
   # imageName: ghcr.io/cloudnative-pg/postgresql:16.6  # Standard image
-  imageName: <YOUR_REGISTRY_URL>/library/cnpg-postgis:16.6-3.4-v2
+  imageName: registry.keyboardvagabond.com/library/cnpg-postgis:16.6-3.4-v2
 
     # Bootstrap with initial database and user
   bootstrap:
@@ -31,20 +31,21 @@ spec:
         - CREATE EXTENSION IF NOT EXISTS postgis_tiger_geocoder;
 
 
-  # PostgreSQL configuration for conservative scaling (3GB memory limit)
+  # PostgreSQL configuration for conservative scaling (4GB memory limit)
   postgresql:
     parameters:
-      # Performance optimizations for 3GB memory limit
-      max_connections: "300"
-      shared_buffers: "768MB"  # 25% of 3GB memory limit  
-      effective_cache_size: "2.25GB"  # ~75% of 3GB memory limit  
-      maintenance_work_mem: "192MB"   # Scaled for 3GB memory limit
+      # Performance optimizations for 4GB memory limit
+      # Reduced max_connections based on actual usage (7 connections observed)
+      max_connections: "150"
+      shared_buffers: "1GB"  # 25% of 4GB memory limit  
+      effective_cache_size: "3GB"  # ~75% of 4GB memory limit  
+      maintenance_work_mem: "256MB"   # Scaled for 4GB memory limit
       checkpoint_completion_target: "0.9"
       wal_buffers: "24MB"
       default_statistics_target: "100"
       random_page_cost: "1.1"  # Good for SSD storage
       effective_io_concurrency: "200"
-      work_mem: "12MB"  # Conservative: 300 connections = ~3.6GB total max
+      work_mem: "24MB"  # Increased from 14MB: 150 connections × 24MB = 3.6GB max
       min_wal_size: "1GB"
       max_wal_size: "6GB"
       
@@ -93,7 +94,7 @@ spec:
       memory: 1.5Gi
     limits:
       cpu: 2000m
-      memory: 3Gi
+      memory: 4Gi
 
   # Enable superuser access for maintenance
   enableSuperuserAccess: true
@@ -159,7 +160,7 @@ spec:
   #       secretAccessKey:
   #         name: postgresql-s3-backup-credentials
   #         key: AWS_SECRET_ACCESS_KEY
-  #     endpointURL: <REPLACE_WITH_S3_ENDPOINT>
+  #     endpointURL: https://s3.eu-central-003.backblazeb2.com
   #     
   #     # Backblaze B2 specific configuration
   #     data: