Up arrow to fill in last prompt

First of all guys thanks for making this plugin

When I am using amazon q in vscode I sometimes get `read ECONNRESET`. I am seeing the same thing happening in this plugin. However I would normally just use the up arrow key to fill the input area with the last submitted message.

Would love to see this added.

No file, test, or entry point is named in the issue. Start by locating the plugin's prompt input and history handling, then verify how the up arrow is currently processed; done means the previous submitted message reliably fills the input area without breaking existing input behavior.

Written by the indexing model from the issue text.