Why: Agent-System-UI and Agent-Squad merged and passed main CI; only this Dev PR remains.
Evidence: main CI statuses on a313d45 (UI) and 9ded893 (Squad) (GATE); task-sync on 32ccecb (SELF).
Impact: planning record and task card only.
Refs: https://git-home.u1680832.nyat.app:30319/weichen/Agent-System-Dev/pulls/602
Co-authored-by: Cursor <cursoragent@cursor.com>