chore: update Grafana to 12.3.1 and PostgreSQL to 18

- Update Grafana from 12.0.2 to 12.3.1 (latest stable)
- Update PostgreSQL from 15 to 18 in docker-compose and Helm
- Update Grafana datasource postgresVersion from 1500 to 1800

PostgreSQL 18 brings up to 3x I/O performance improvements and better
index utilization. pgwatch v3 supports PostgreSQL 14-18 with version-aware
queries that automatically adapt.

Author: claude

config/grafana/provisioning/datasources/datasources.yml

@@ -12,7 +12,7 @@ datasources:
       password: pgwatchadmin
     jsonData:
       sslmode: disable
-      postgresVersion: 1500
+      postgresVersion: 1800
     isDefault: false
 
   - name: PGWatch-Prometheus

docker-compose.yml

@@ -24,7 +24,7 @@ services:
 
   # Target Database - The PostgreSQL database being monitored (demo only)
   target-db:
-    image: postgres:15
+    image: postgres:18
     container_name: target-db
     environment:
       POSTGRES_DB: target_database
@@ -53,7 +53,7 @@ services:
   # and postgres-exporter connectivity without compromising security since
   # the database is not exposed externally.
   sink-postgres:
-    image: postgres:15
+    image: postgres:18
     container_name: sink-postgres
     environment:
       POSTGRES_DB: postgres
@@ -135,7 +135,7 @@ services:
 
   # Grafana with datasources - Visualization layer
   grafana:
-    image: grafana/grafana:12.0.2
+    image: grafana/grafana:12.3.1
     container_name: grafana-with-datasources
     environment:
       GF_SECURITY_ADMIN_USER: monitor

postgres_ai_helm/templates/grafana-datasources.yaml

@@ -29,7 +29,7 @@ data:
         jsonData:
           database: {{ .Values.sinkPostgres.database }}
           sslmode: disable
-          postgresVersion: 1500
+          postgresVersion: 1800
         secureJsonData:
           password: {{ .Values.secrets.postgres.password }}
       {{- if .Values.flask.enabled }}

postgres_ai_helm/values.yaml

@@ -30,7 +30,7 @@ global:
   customTags: {}
 
 sinkPostgres:
-  image: postgres:15
+  image: postgres:18
   database: measurements
   user: pgwatch
   resources: {}