[FEATURE] Stash should work as stack, not only single slot

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

I often keep a stashed prompt for later using ctrl-s, great feature. However it happens that before using it again, I want to save another prompt.

Proposed Solution

It would be very useful if this would not overwrite a previous stashed prompt, which can happen accidentally and looses input but it would also be useful as a feature. Instead, it would be great if this was stacked, similar to how stashes work in git. When ctrl-s is issued and there is a pending prompt, add it as a new item on top of the stack. If the input is empty, pop from the stack, basically the same interface it has now without overwriting.

Alternative Solutions

Prevent overwriting the stashed prompt when using ctrl-s again and something is already in the single stash in order to prevent loosing the prompt accidentally. Claude code would then reject stashing with a message and keep the current prompt as is

Priority

Medium - Would be very helpful

Feature Category

Interactive mode (TUI)

Use Case Example

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Additional Context

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