[Bug]: Ability to define initial instructions.

### Platform

macOS

### Operating system version

macOS Tahoe 26.3 (25D125)

### System architecture

ARM64 (M1, M2, etc)

### PolyScope Version

0.7.0

### Bug description

This isn't a bug, but rather a feature request: it would be great to have a way to set initial instructions when creating a new workspace.

### Steps to reproduce

_No response_

### Relevant log output

```shell

```