Settle run usage

const { result, error } = await unprice.runs.settle({
  runId: "brun_123",
  featureSlug: "ai-output-tokens",
  eventSlug: "completions",
  idempotencyKey: "run:req_123:settle",
  properties: { outputTokens: 620 }
});

if (error) throw new Error(`${error.code}: ${error.message}`);

if (!result.accepted) {
  throw new Error(`Settlement needs review: ${result.reason}`);
}

// End only after all billable usage has been settled successfully.
const { error: endError } = await unprice.runs.end({
  runId: "brun_123",
  status: "completed"
});

if (endError) throw new Error(`${endError.code}: ${endError.message}`);