fix: ensure reasoning tokens arent double counted when calculating usage (#21047)

packages/opencode/src/session/index.ts

@@ -278,7 +278,7 @@ export namespace Session {
     const tokens = {
       total,
       input: adjustedInputTokens,
-      output: outputTokens,
+      output: outputTokens - reasoningTokens,
       reasoning: reasoningTokens,
       cache: {
         write: cacheWriteInputTokens,