When starting a new session using the "Create from.

When starting a new session using the "Create from..." button/pop-up it would be great and more intuitive I can also choose local branches to base my new session on so I can have a session setting up a worktree based on a different local worktree that is just not pushed/merged yet.

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| Field | Value |
| --- | --- |
| App version | 1.0.18 |
| OS | Windows 10.0.26100 |
| Theme | Fox |
| Path | /chat |
| Tenure | Week 7 |

Start from the desktop app's "Create from..." button and pop-up, then trace how available branches are presented and how a new session's worktree is created. Done means local branches, including unpushed branches from another local worktree, can be selected as the basis for a new session; verify the flow on Windows.

Written by the indexing model from the issue text.