Returns the Copilot configuration for the given account. Returns platform defaults (enabled=false, …) for accounts with no row. accountId is required; the endpoint never falls back to the calling principal because the caller is a service identity with no tenant scope of its own.

Read-side DTO for the AI Copilot tenant configuration (IDT-788). Returned by both the admin UI endpoint (/v1/admin/copilot/config) and the internal sidecar endpoint (/api/copilot/config). If no row exists for the tenant, the service returns this DTO populated with platform defaults rather than inserting a row eagerly — the row is created on first PUT.

Multi-department (brand) support: config is keyed by (AccountId, DepartmentId). Infoset.Types.Models.Admin.CopilotConfigDto.DepartmentId = 0 is the account-level default row; department-scoped rows carry the actual brand id. A department read with no row falls back to the account-level (dept 0) row as a whole, and the returned Infoset.Types.Models.Admin.CopilotConfigDto.DepartmentId reflects the ACTUAL row served (0 after a fallback), not the requested department.

Infoset.Types.Models.Admin.CopilotConfigDto.SelectedDeskIds is the set of help-center desk ids this config applies to. The distinction between null and empty is meaningful and preserved end-to-end: <list type="bullet"><item>null — DB column is NULL — "all desks" (no restriction).</item><item>empty array — DB column is the empty string — "no desks".</item><item>non-empty — DB column is a comma-separated list of desk ids.</item></list>