On the default local in-process backend, an approval card whose stream
ended while still pending (cancel/fork/provider-error/completion) left the
agent queue entry dropped and the _pending mirror reconciled away. Clicking
Approve/Deny then sent an approval_id that matched nothing, so the handler
returned a bare {ok:false}; since #4771 the frontend surfaces that as
'Approval response not accepted.' with a stuck card (reported by
@santastabber on v0.51.666 and b3nw).
Distinguish a genuinely stale card (no pending approval for the session ->
benign {ok:true, stale_cleared:true} so the UI clears the orphan) from a
stale-id click made while a DIFFERENT approval is live (still ok:false so it
can never resolve the wrong command -- #527 guard preserved). Frontend
clears the orphan card on stale_cleared even if the displayed id drifted.
Co-authored-by: b3nw <b3nw@users.noreply.github.com>
