Rewind can land on an assistant message and clears its own queued rerun

What

Rewind takes a conversation back to an earlier message. Two changes affect it:

• The lookup that finds where to rewind to takes a new allowAssistantTarget option. When no message you sent matches, it can now return one of Claude's replies (an assistant message) instead. Before, it returned only a message you sent, or nothing.
• New helpers clean up what the rewound turn left in the message queue, the list of prompts waiting to run. One withdraws saved endings of MCP tasks (long jobs run by tools connected through the Model Context Protocol). Another removes queued prompt commands that the rewound turn itself produced, depending on a switch. When it declines, it records why: not_a_prompt, opener_unknown, turn_unseen, answers_for_others, others_queued, no_cut, or switch_<state>.

Why

A turn you rewind away from should not run again from the queue afterwards. Where the option is used, a rewind can also land on one of Claude's replies rather than only on your own messages.