Resume a suspended workspace (admitted like a start)

Creates a resume operation for a suspended workspace, or an open recovery for a failed workspace (same ID and disk, no reset), or returns the active resume/open (concurrent wakes join one operation); 202 with it: poll GET /operations/{id}. Errors: 409 already_running or not_suspended, operation_in_progress (a suspend or another operation is active; details.active_operation_id), workspace_deleted, not_supported_for_mode (file-first); 402/403/429 as for open (admitted like a start). Supports Idempotency-Key. Held resume: with Prefer: wait=<seconds> (at most 20) the response is held until the operation is terminal or the wait elapses, exactly like a held open; success answers 200 with the running workspace, the succeeded operation, cell_endpoint and a tool token for agent_label/tools (minted while the restore is in flight, at the new ownership epoch), Preference-Applied: wait=<seconds>; anything else is 202 with the fresh operation. With the preference a workspace that is already running answers 200 at once (operation null, a token) instead of 409 already_running. Without Preference-Applied the server did not wait: poll the operation. tools beyond the principal’s tool permissions are 403 (nothing is created); a token the API cannot issue otherwise is tool_token: null. Plan concurrency: a start the plan’s concurrent_workspaces limit refuses is queued on the request (up to 10 s) and admitted as soon as one of the organization’s workspaces frees; if none does, 429 quota_exceeded with Retry-After: 2 (retryable; details limit concurrent_workspaces, limit_value, current, retry_after_seconds, plan). Nothing was created: retry after Retry-After, with the same Idempotency-Key or a new one. With Prefer: wait the queued time counts against the wait.