Web Shell backend-authoritative queue display

Problem

The Web Shell keeps a local unknown queue row when a pending-prompt or mid-turn admission request may have reached the daemon but its response was lost. A later daemon refresh can then add the authoritative row beside the local copy, producing duplicate-looking entries and UI such as “delivery unknown” or “local copy discarded”.

Design

Local rows exist only while an admission request is in flight. After the request settles, both admission paths query the daemon and render its queue snapshot. If the request or the follow-up query fails, the local row is removed; a later reconnect or queue event can restore it only if the daemon reports it.

Failures after dispatch follow the same rule and do not restore the payload into the editor. Failures before either admission request is dispatched, such as media upload failure, restore the draft because the daemon could not have accepted it.

The obsolete unknown-admission row state and its restore/discard UI are removed.