granthi-sync v1: granthi-link provisioning service + client daemon + tests

Co-Authored-By: Claude Fable 5 <[email protected]>

server/granthi-link.service

@@ -0,0 +1,17 @@
+[Unit]
+Description=granthi-link provisioning service (granthi-sync spine)
+After=network-online.target docker.service
+Wants=network-online.target
+
+[Service]
+Type=simple
+ExecStart=/usr/bin/python3 /opt/granthi-link/granthi_link.py /opt/granthi-link/config.json
+Restart=on-failure
+RestartSec=3
+User=root
+NoNewPrivileges=true
+ProtectSystem=full
+ReadWritePaths=/opt/granthi-link
+
+[Install]
+WantedBy=multi-user.target