[FEATURE] Allow `/fork` while claude is working

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

Why can't I spawn /fork while claude is working?
This is when the ability to spawn a background agent is most needed! I don't want to press esc to stop claude, create /fork, and then write to the main claude to continue. I want to just write /fork do x and it will work.

Proposed Solution

You can /fork a background agent if you remember something while Claude is working

Alternative Solutions

_No response_

Priority

High - Significant impact on productivity

Feature Category

Interactive mode (TUI)

Use Case Example

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Additional Context

_No response_