fix(docker-compose): adapt Postgres volume path for Postgres 18+

PostgreSQL 18+ changed its default PGDATA layout from
/var/lib/postgresql/data → /var/lib/postgresql/MAJOR/docker.
This update aligns the docker-compose configuration with
the new convention per docker-library/postgres#1259 to ensure
containers start correctly on Postgres 18+.

References:
- docker-library/postgres#1259
- docker-library/postgres#37

Author: Jermiah Jerome

docker-compose.yml

@@ -1,30 +1,31 @@
-version: "3.8"
+  version: "3.8"
 
-services:
-  demo-night-app-redis:
-    image: redis
-    ports:
-      - "6379:6379"
+  services:
+    demo-night-app-redis:
+      image: redis
+      ports:
+        - "6379:6379"
 
-  demo-night-app-serverless-redis-http:
-    ports:
-      - "8079:80"
-    image: hiett/serverless-redis-http:latest
-    environment:
-      SRH_MODE: env
-      SRH_TOKEN: localhost_test_token
-      SRH_CONNECTION_STRING: "redis://demo-night-app-redis:6379" # Using `demo-night-app-redis` hostname since they're in the same Docker network.
+    demo-night-app-serverless-redis-http:
+      ports:
+        - "8079:80"
+      image: hiett/serverless-redis-http:latest
+      environment:
+        SRH_MODE: env
+        SRH_TOKEN: localhost_test_token
+        SRH_CONNECTION_STRING: "redis://demo-night-app-redis:6379" # Using `demo-night-app-redis` hostname since they're in the same Docker network.
 
-  demo-night-app-postgres:
-    image: postgres
-    environment:
-      POSTGRES_DB: demo-night-app
-      POSTGRES_USER: postgres
-      POSTGRES_PASSWORD: password
-    ports:
-      - "5432:5432"
-    volumes:
-      - postgres-data:/var/lib/postgresql/data
+    demo-night-app-postgres:
+      image: postgres
+      environment:
+        POSTGRES_DB: demo-night-app
+        POSTGRES_USER: postgres
+        POSTGRES_PASSWORD: password
+        PGDATA: /var/lib/postgresql/18/docker 
+      ports:
+        - "5432:5432"
+      volumes:
+        - postgres-data:/var/lib/postgresql
 
-volumes:
-  postgres-data:
+  volumes:
+    postgres-data: