It looks like worktrees are implicitly created for sessions.

It looks like worktrees are implicitly created for sessions. I think that there should be some prompt, at least the first time, to ask what branch the worktree should be created from.

For example, I was working my local dotnet/roslyn repo, which has both `origin` and `upstream` remotes. My `origin/master` branch is from ~2021. I think `upstream` has no `master` branch--we migrated from `master`->`main` naming. So I was super confused when the agent could not find stuff that I expected to be there.

If it had just asked me first (possibly recommending a default), what branch/ref to create the worktree off of, then the confusion could have been avoided.

---
| Field | Value |
| --- | --- |
| App version | 1.1.3 |
| OS | Windows 10.0.26200 |
| Theme | GitHub |
| Path | /chat |
| Tenure | Day 1 |

Inizia tracciando il flusso della sessione che crea implicitamente dei worktree, quindi riproducilo con un repository che abbia più remotes e branch predefiniti diversi. Verifica come viene determinata attualmente la selezione di branch/ref. Il lavoro è completato quando la prima sessione rilevante chiede il branch o la ref di base per il worktree, con un valore predefinito chiaro, ed evita di scegliere silenziosamente un branch inatteso.

Scritto dal modello di indicizzazione a partire dal testo della issue.