Add PostgreSQL integration with EF Core + Notes demo page

compose.yaml

@@ -1,9 +1,33 @@
 services:
+  postgres:
+    image: postgres:16
+    container_name: freman.sample.postgres
+    environment:
+      POSTGRES_DB: freman_sample
+      POSTGRES_USER: appuser
+      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD:-CHANGE_ME}
+    ports:
+      - "5432:5432"
+    volumes:
+      - freman_sample_pgdata:/var/lib/postgresql/data
+    healthcheck:
+      test: [ "CMD-SHELL", "pg_isready -U appuser -d freman_sample" ]
+      interval: 5s
+      timeout: 3s
+      retries: 20
+      
   freman.sample.web:
     image: freman.sample.web
     build:
       context: .
       dockerfile: Freman.Sample.Web/Freman.Sample.Web/Dockerfile
+    depends_on:
+      postgres:
+        condition: service_healthy
+    environment:
+      ASPNETCORE_ENVIRONMENT: Development
+      ConnectionStrings__AppDb: Host=postgres;Port=5432;Database=freman_sample;Username=appuser;Password=${POSTGRES_PASSWORD:-CHANGE_ME}
+
 
   freman.sample.web.client:
     image: freman.sample.web.client
@@ -11,3 +35,5 @@
       context: .
       dockerfile: Freman.Sample.Web/Freman.Sample.Web.Client/Dockerfile
 
+volumes:
+  freman_sample_pgdata: