Gemini CLI Shell Command does not support aliases

[jacob314]

Repro steps:
Set an alias in your .bash_profile or similar
alias baz=echo

Verify that this alias does not work from Gemini CLI
e.g running
! baz hello

while return an error rather than echoing hello.

Solving this likely involves changing how we run shell scripts as we only want to pay the cost of spawning a shell that reads the full .bash_profile once per session.

This may be a little risky so should be implemented as a setting first.

Other CLIs support this robustly. The fact that we don't makes it confusing for users to know what shell commands they can run in their CLI.

Other problems that a solution for this should likely solve:

1. Persisting env variables between shells run by the same Gemini CLI instance.

[gemini-cli]

Found possible duplicate issues:

• Custom Shell Commands, Aliases, or Functions Fail to Execute in Gemini CLI Environment #3615
• Shell mode cannot recognize alias. #3793

If you believe this is not a duplicate, please remove the status/possible-duplicate label.

[jacob314]

#3615 which originally reported this got a decent number of upvotes. Has also been reported by g3 users.