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

Dockerfile

@@ -0,0 +1,16 @@
+FROM registry:2
+
+# Install Apache utilities for htpasswd management
+RUN apt-get update && apt-get install -y \
+    apache2-utils \
+    && rm -rf /var/lib/apt/lists/*
+
+# Create auth directory
+RUN mkdir -p /etc/docker/registry/auth
+
+# Copy custom entrypoint script
+COPY entrypoint.sh /usr/local/bin/
+RUN chmod +x /usr/local/bin/entrypoint.sh
+
+ENTRYPOINT ["/usr/local/bin/entrypoint.sh"]
+CMD ["/etc/docker/registry/config.yml"]