shell prompt no longer shows cwd/git branch; request configurable display #1349

Summary

In recent versions of kimi-cli, the shell prompt no longer shows current working directory (cwd) and git branch info.
This makes it harder to verify repo/context during interactive work.

Current behavior

Prompt only shows symbols like ✨ / 💫 / $, without cwd or branch.

Expected behavior

Either:

1. Restore cwd + git branch in prompt, or
2. Provide config toggles (recommended), e.g.:
   • shell.prompt_show_cwd
   • shell.prompt_show_git

Why this matters

When switching sessions/repositories frequently, visible cwd/branch helps avoid operating in the wrong repo/branch.

Additional context

Commit 4c28b6d simplified prompt display and removed username/cwd style prefix.
The request is mainly for optional configurability so the current minimal prompt can remain default.