fix: rebuild without cache and simplify Dockerfile

- Force no-cache build in docker-compose
- Simplify Dockerfile to use Alpine package manager
- Clean up configuration

docker-compose.yml

@@ -2,7 +2,10 @@ version: '3.8'
 
 services:
   registry:
-    build: .
+    build:
+      context: .
+      dockerfile: Dockerfile
+      no-cache: true
     container_name: registry
     restart: unless-stopped
     expose: