Feature Request: Support for configurable base_branch in environment.toml

What variant of Codex are you using?

App

What feature would you like to see?

Currently, the application defaults to using main (or the repository's default branch) when creating new worktrees or performing branch-related operations. In environments where the primary development happens on a dev branch, users must manually select the base branch every time a new worktree is created, which adds unnecessary friction to the workflow.

Please add a new configuration option in environment.toml to specify the default base branch.

[git]
base_branch = "dev"

Additional information

_No response_