🐛 fix: correct totalOutputTokens calculation for XAI provider (#8984)

Author: bbbugg

packages/model-runtime/src/utils/usageConverter.test.ts

@@ -271,7 +271,7 @@ describe('convertUsage', () => {
     // Assert
     expect(xaiResult).toMatchObject({
       totalInputTokens: 6103,
-      totalOutputTokens: 66,
+      totalOutputTokens: 447, // 66 + 381，xai的reasoning_tokens和completion_tokens价格一样
       outputTextTokens: 66, // 不减去 reasoning_tokens
       outputReasoningTokens: 381,
       totalTokens: 6550,

packages/model-runtime/src/utils/usageConverter.ts

@@ -27,6 +27,8 @@ export const convertUsage = (
     provider === 'xai'
       ? totalOutputTokens - outputAudioTokens
       : totalOutputTokens - outputReasoning - outputAudioTokens - outputImageTokens;
+  const totalOutputTokensNormalized =
+    provider === 'xai' ? totalOutputTokens + outputReasoning : totalOutputTokens;
 
   const totalTokens = inputCitationTokens + usage.total_tokens;
 
@@ -43,7 +45,7 @@ export const convertUsage = (
     outputTextTokens: outputTextTokens,
     rejectedPredictionTokens: usage.completion_tokens_details?.rejected_prediction_tokens,
     totalInputTokens,
-    totalOutputTokens: totalOutputTokens,
+    totalOutputTokens: totalOutputTokensNormalized,
     totalTokens,
   } satisfies ModelTokensUsage;