[BUG] Hidden and untracked files are not referenced properly by "at" @.env.development - not shown on the selection list

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

When I try to select a hidden file that isn't tracked by Git, the file isn't shown on the list.

What Should Happen?

IMHO, it should still show up, since it's available in the filesystem inside the project's directories.

Error Messages/Logs

Steps to Reproduce

Prereqs:

1. Have a hidden file in your project directory that isn't tracked by git.

Steps:

1. Run claude inside your project directory
2. Try referencing the hidden file with @<filename> notation -> bug! the file doesn't show up in the dropdown list

Claude Model

Sonnet (default)

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.104 (Claude Code)

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

<img width="249" height="304" alt="Image" src="https://github.com/user-attachments/assets/b59557b9-c268-4f15-b772-819b8c86148a" />
<img width="256" height="365" alt="Image" src="https://github.com/user-attachments/assets/278df096-7377-4777-8015-ec43609f3a48" />