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/arke/arke.service.j2

@@ -0,0 +1,24 @@
+[Unit]
+Description=Arke MCP Server
+After=network.target
+Wants=network.target
+
+[Service]
+Type=simple
+User={{arke_user}}
+Group={{arke_group}}
+WorkingDirectory={{arke_directory}}
+EnvironmentFile={{arke_directory}}/.env
+ExecStart={{arke_directory}}/.venv/bin/python {{arke_directory}}/arke.py
+
+Restart=always
+RestartSec=10
+
+# Security
+NoNewPrivileges=true
+PrivateTmp=true
+ProtectSystem=strict
+ProtectHome=true
+
+[Install]
+WantedBy=multi-user.target