🐞 Git Branch detection captures shell outputs rather than just the branch

### Description

In my ZSH configuration (~/.zprofile) I echo text out, this runs when I open a new shell, but the text echoed shows up in the Toolbar's subtitle where it shows the branch.

### To Reproduce

This assumes the same machine configuration as me, since I'm unsure how much of this is CodeEdit's decisions VS my setup, though assuming you run ZSH as your standard shell I'd assume it would replicate properly.

#### open `.zprofile`
```shell
open ~/.zprofile -a CodeEdit
```

#### add an `echo` statement, such as
```shell
echo "This text should not show up in CodeEdit branch info, it should only be seen in interactive shells"
```

#### save `.zprofile`

#### Quite CodeEdit

#### Open a Git initialized repository in CodeEdit

Or make a temporary Git repo and open it...

```shell
setopt INTERACTIVE_COMMENTS
# ↑ allow comments in the shells interactive mode (default off in zsh)

dir="$(mktemp -d)" # makes a temporary folder (so it auto deletes by the OS later)

cd $dir # go to our temporary directory

git init # initialize a Git repository in the directory

open . -a CodeEdit # open our temporary git repo in CodeEdit
```

#### and in the branch section you will see an output like the image attached

### Expected Behavior

CodeEdit runs a non-interactive shell to capture the current branch, and only captures branch info via Git's stdout, rather than the shell contents

### Version Information

CodeEdit: 0.3.6 (47)
macOS: 26.1.0

### Additional Context

_No response_

### Screenshots

首先跟踪 CodeEdit 的 Git 分支检测，以及用于填充 Toolbar 副标题的 shell 命令；issue 未指定文件或测试。通过在 ~/.zprofile 中添加 echo 语句并打开一个 Git 仓库来复现，然后确认只显示分支，且排除 shell 输出。

由索引模型根据 Issue 内容生成。