web: SSE reconnect race on approval card rendering

[CrazyWillBear]

Issue

SSE reconnect (es.onopen) fires async reloadHistory (replaceChildren) while the new /events subscription immediately streams the replayed pending approval frame. If addApproval renders before the clear lands, the card is wiped and not re-added, briefly regressing AC4 (watched blocked thread must show the card).

Location

src/chief/web/script_tools.py:94

Root cause

Same root cause as the medium priority fix in #267.

Status

• Ordering-dependent, unverified

Blocked by

#267