Package portable grid agent operation (#134)

packaging/metacrate-grid-agent/systemd/grid-agent.env.example

@@ -0,0 +1,7 @@
+# Values here are paths and non-secret mode settings only. Never put secret
+# values in this file. Create every referenced file as mode 0600, owned by the
+# metacrate-agent service identity.
+METACRATE_AGENT_LLM_API_KEY_FILE=/etc/metacrate/secrets/llm-api-key
+METACRATE_AGENT_GRID_PASSWORD_FILE=/etc/metacrate/secrets/grid-password
+METACRATE_AGENT_CONTROL_OPERATOR_TOKEN_FILE=/etc/metacrate/secrets/control-operator-token
+METACRATE_AGENT_STORAGE_PATH=/var/lib/metacrate/grid-agent