Include reasoning messages in cloud tasks (#8401)

Author: mrubens

src/core/task/Task.ts

@@ -2252,6 +2252,22 @@ export class Task extends EventEmitter<TaskEvents> implements TaskLike {
 				// Note: updateApiReqMsg() is now called from within drainStreamInBackgroundToFindAllUsage
 				// to ensure usage data is captured even when the stream is interrupted. The background task
 				// uses local variables to accumulate usage data before atomically updating the shared state.
+
+				// Complete the reasoning message if it exists
+				// We can't use say() here because the reasoning message may not be the last message
+				// (other messages like text blocks or tool uses may have been added after it during streaming)
+				if (reasoningMessage) {
+					const lastReasoningIndex = findLastIndex(
+						this.clineMessages,
+						(m) => m.type === "say" && m.say === "reasoning",
+					)
+
+					if (lastReasoningIndex !== -1 && this.clineMessages[lastReasoningIndex].partial) {
+						this.clineMessages[lastReasoningIndex].partial = false
+						await this.updateClineMessage(this.clineMessages[lastReasoningIndex])
+					}
+				}
+
 				await this.persistGpt5Metadata(reasoningMessage)
 				await this.saveClineMessages()
 				await this.providerRef.deref()?.postStateToWebview()