Replace db-ui with pgAdmin 4 for better cross-platform compatibility

DOCKER COMPOSE:

- Replaced ghcr.io/n7olkachev/db-ui with dpage/pgadmin4:latest

- Added pgadmin_data volume for persistent configuration

- Configured pgAdmin with default credentials

- Port mapping: 3000:80 (pgAdmin runs on port 80 internally)

DOCUMENTATION:

- Updated README.md with pgAdmin login instructions and first-time setup

- Updated QUICKSTART.md with detailed pgAdmin configuration steps

- Added server connection details for easy setup

BENEFITS:

- pgAdmin has proper multi-platform support (linux/amd64, linux/arm64, etc.)

- Industry-standard PostgreSQL management tool

- More features: query builder, schema visualization, data import/export

- Better documentation and community support

docker-compose.yml

@@ -30,24 +30,24 @@ services:
       retries: 5
     restart: unless-stopped
 
-  db-ui:
-    image: ghcr.io/n7olkachev/db-ui:latest
-    platform: unknown/unknown
+  pgadmin:
+    image: dpage/pgadmin4:latest
     container_name: business_analytics_ui
     environment:
-      POSTGRES_HOST: postgres
-      POSTGRES_USER: data_analyst
-      POSTGRES_PASSWORD: SecurePass123!
-      POSTGRES_DB: business_analytics
-      POSTGRES_PORT: 5432
+      PGADMIN_DEFAULT_EMAIL: admin@businessanalytics.local
+      PGADMIN_DEFAULT_PASSWORD: SecurePass123!
+      PGADMIN_CONFIG_SERVER_MODE: 'False'
+      PGADMIN_CONFIG_MASTER_PASSWORD_REQUIRED: 'False'
     ports:
-      - "3000:3000"
+      - "3000:80"
     networks:
       - analytics_network
     depends_on:
       postgres:
         condition: service_healthy
     restart: unless-stopped
+    volumes:
+      - pgadmin_data:/var/lib/pgadmin
 
 networks:
   analytics_network:
@@ -56,4 +56,6 @@ networks:
 volumes:
   postgres_data:
     driver: local
+  pgadmin_data:
+    driver: local