gram-management-api

Concepts, external interfaces, and conventions for Gram's management API — the Goa-designed HTTP-RPC surface under `/rpc/<service>.<method>` that powers the dashboard, CLI, and public SDK. Activate whenever the task involves designing, implementing, or modifying a management endpoint (new service, new method, payload/result changes, OpenAPI/SDK surface changes, CLI changes, wiring a new service into the server).