Record the streaming display pull request on the task card

Why: The task card is the review record, and it still pointed at a placeholder after the pull request existed.
Evidence: Dev pull request 147 is open.
Impact: The card status stays in progress until merge.
Refs: feature/stream-display-overhaul
Co-authored-by: Cursor <cursoragent@cursor.com>

.task/feature-stream-display-overhaul.md

@@ -1,6 +1,6 @@
 # feature/stream-display-overhaul 任务卡
 
-任务主记录：<PR 链接，task-finish 时填写>；状态：进行中；owner：weichen
+任务主记录：https://git-home.u1680832.nyat.app:30319/weichen/Agent-System-Dev/pulls/147 ；状态：进行中；owner：weichen
 
 ## 基线与授权