Get the current copilot suggestion snapshot for a ticket, proxied from copilot-service. Ticket analog of `GET /v1/chat/rooms/{roomId}/suggestions`. Returns the raw DTO — NOT wrapped in `ApiResponse` — to mirror the chat suggestions endpoint and the shape the ticket FE hook consumes (reads `.suggestions` off the body directly). FAIL-OPEN: copilot-service being unconfigured, slow or down yields an empty snapshot (200 with an empty list), never an error.