Clearing the retry from the mirror effect raced: an async command continuation
can open a prompt and install its retry before a previous commit's passive
effect flushes, and that effect's stale `pendingStepUp === null` snapshot would
then delete the new prompt's retry.
Install it in `trySetPendingStepUp` instead, in the same synchronous step that
opens the prompt — `null` for an ambient prompt, the operation for a
command-scoped one. Every prompt comes through there and `handleStepUpAuthorize`
is the only reader, so a slot cleared as a side effect can leave a stale closure
behind harmlessly: the next prompt overwrites it. A refused prompt still
installs nothing (#2165).
Copilot round 3 on #2237.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S4WZSxx6XMKzRdgPce9CAd
Signed-off-by: cliffhall <cliff@futurescale.com>
258e7f1526