'!' (bash mode) runs a non-interactive shell — ~/.zshrc not sourced, aliases not expanded

Description

When using bash mode via ! in Claude Code, the shell is non-interactive. This has two consequences:

1. ~/.zshrc is not sourced (it is only loaded by interactive shells).
2. Alias expansion is disabled — aliases defined in ~/.zshrc (or anywhere) do not work.

Steps to Reproduce

Define an alias in ~/.zshrc:

alias gst="git status"

Then in Claude Code bash mode:

! gst
# => command not found: gst

Expected Behavior

! mode feels like an interactive shell to the user. It should either:

• Launch a proper interactive shell (sourcing ~/.zshrc, enabling alias expansion), or
• Document that it is non-interactive and aliases will not work.

Environment

• macOS (zsh)
• Claude Code CLI