refactor: restructure registry with auth and agent guidelines

- Add built-in authentication with Apache utils
- Add AGENTS.md for coding guidelines
- Enhance security with authentication enabled by default
- Remove unnecessary template files
- Simplify configuration and setup process

entrypoint.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+
+# Initialize auth file if it doesn't exist
+if [ ! -f /etc/docker/registry/auth/htpasswd ]; then
+    echo "Initializing auth file with default user 'recruas'"
+    htpasswd -B -c /etc/docker/registry/auth/htpasswd recruas
+    echo "Auth file created. Default user: recruas"
+fi
+
+# Start the registry
+exec /bin/registry /etc/docker/registry/config.yml "$@"