build: load secrets from .env instead of hardcoding

compose.yml

@@ -3,11 +3,11 @@ services:
     image: docker.io/library/postgres:16
     restart: unless-stopped
     environment:
-      - POSTGRES_USER=postgres
-      - POSTGRES_PASSWORD=pass
-      - POSTGRES_DB=loft
+      - POSTGRES_USER=${POSTGRES_USER}
+      - POSTGRES_PASSWORD=${POSTGRES_PASSWORD}
+      - POSTGRES_DB=${POSTGRES_DB}
     ports:
-      - "5432:5432"
+      - "127.0.0.1:5432:5432"
     volumes:
       - loft_db_data:/var/lib/postgresql/data
     healthcheck:
@@ -26,10 +26,10 @@ services:
       db:
         condition: service_healthy
     environment:
-      - DATABASE_URL=postgres://postgres:pass@db:5432/loft
-      - STORAGE_PATH=/app/storage
+      - DATABASE_URL=${DATABASE_URL}
+      - STORAGE_PATH=${STORAGE_PATH}
     volumes:
-      - loft_storage:/app/storage
+      - loft_storage:${STORAGE_PATH}
   
 volumes:
   loft_db_data: