fix(chat): activity row (Bot avatar + shimmer) gone after send on DSH 0.2.1 — RUNNING_HOST direct-child selector misses nested RunningStatus #1626

Written-by: Grok Bot (box-local; no Cursor CloudAgent)

Context

Owner (2026-10-29 Asia/Shanghai, t685u–t687u on bot-im): after sending a message the Bot avatar + short blinking/shimmer status text is gone; the area near the transcript foot / composer looks empty or like vanilla DeepSeek Harness. Screenshot: red box on the empty bottom-left chrome. Related reports: #1586 busy-ack (merged; does not restore the typing row), #1624 empty 「思考过程」 strip (claimed separately; may share the blank-while-working feel), #1509 steer/tool-wait interrupt (claimed separately; not this UI host).

Actual

FlyBot replaces DSH's RunningStatus whale with .bt-typing (BotMark + shimmer phrase) by portaling into [data-chat-running]. CSS also hides DSH's native spans inside that host ([data-chat-running]>span:not([role=status])).

On DSH 0.2.1-rc.2 (pinned in #1594 / v0.2.13), RunningStatus moved from a direct child of [data-chat-flow] into the new conversation.chat.flow slot (ChatFlow.tsx appends <RunningStatus/> inside [data-slot="conversation.chat.flow"]).

FlyBot still uses a direct-child selector:

• RUNNING_HOST = '[data-chat-flow] > [data-chat-running]' in core/src/client/activity-row.js
• findHost uses flow.querySelector(':scope > [data-chat-running]')
• BusyAckBubble (fix(chat): short spoken ack when a message is accepted while busy #1586) reuses the same RUNNING_HOST

So document.querySelector(RUNNING_HOST) returns null → ActivityIndicator / BusyAckBubble return null → DSH whale stays CSS-hidden → empty chrome. Without the FlyBot row, the chat foot feels like broken/native DSH.

Expected

While a turn is running (and not streaming text), the Bot avatar + shimmer phrase (.bt-typing) appears promptly after send in the running-status host, as before the 0.2.1 pin.

Fix scope

• Widen RUNNING_HOST / findHost to find [data-chat-running] under [data-chat-flow] whether nested in the flow slot (0.2.1) or direct (0.2.0).
• Keep CSS hide of DSH spans; do not restore the whale.
• Tests + changelog. Box-local; no CloudAgent; no LIVE/prod.
• Do not conflate with Workflow fix(workflow): Runs drawer — duration gap before status chip; Failed once #1619/fix(workflow): Runs drawer — duration collides with Done chip; Failed rows double-draw an F #1618 UI or implement fix(chat): human Steer while a tool/job wait is open does not interrupt — only Stop aborts #1509 interrupt here.

Repro

1. Own Bot chat on a build with DSH 0.2.1-rc.2 (e.g. v0.2.13+).
2. Send a short message.
3. Watch the area under the transcript / above the composer: no Bot avatar + shimmer; empty or native-feeling chrome.