docs: rewrite README with structured overview and quick start guide

Replaces the minimal project description with a comprehensive README
including a component overview table, quick start instructions, common
Ansible operations, and links to detailed documentation. Aligns with
Red Panda Approval™ standards.

ansible/mcpo/mcpo.service.j2

@@ -0,0 +1,15 @@
+[Unit]
+Description=MCPO
+After=network.target
+
+[Service]
+Type=simple
+User={{mcpo_user}}
+Group={{mcpo_group}}
+WorkingDirectory={{mcpo_directory}}
+ExecStart={{mcpo_directory}}/.venv/bin/mcpo --port {{mcpo_port}} --config {{mcpo_directory}}/config.json
+Restart=always
+RestartSec=3
+
+[Install]
+WantedBy=multi-user.target