make folder to house worktrees configurable

Problem

At the moment, repositories and their worktrees need to exist under the same parent folder. This creates a workflow issue for users who use IDEs and other development tools.

For example, I keep my repositories in a directory that I open in IntelliJ IDEA and several other tools. When worktrees are created alongside the repositories, those tools detect each worktree as a separate Git project, cluttering the workspace with additional projects and diffs that I don't want to see.

Proposed Solution

It would be very helpful if the location where worktrees are created could be made configurable.

This would allow users to:

Keep their primary repository directory clean.
Store worktrees in a separate location dedicated to temporary or parallel work.
Avoid IDEs and other tooling automatically detecting every worktree as an additional Git project.

---
| Field | Value |
| --- | --- |
| App version | 1.0.22 |
| OS | macOS 26.4.1 |
| Theme | GitHub |
| Path | /chat |
| Tenure | Week 2 |

Empieza por localizar el flujo de creación de worktrees y la interfaz de configuración de la app. Traza cómo se selecciona la carpeta padre actual, luego define un destino configurable para los nuevos worktrees y verifica que los repositorios puedan permanecer separados de sus worktrees.

Escrito por el modelo de indexación a partir del texto del issue.