Codex extension in VSCode: Search with @ does not find files inside dot-directories unless query starts with "@."

What version of the VS Code extension are you using?

0.4.12

Which IDE are you using?

VS Code

What platform is your computer?

Linux 6.14.0-29-generic x86_64 x86_64

What steps can reproduce the bug?

1. Create a minimal workspace:

``
EXAMPLE_BUG/
├─ .bug/
│ └─ file_hidden.txt
├─ visible_folder/
│ └─ file_showing.txt
└─ file_in_root.txt
``

1. Open EXAMPLE_BUG with the Codex extension.
2. In the file search box, type @file_hidden.txt → No results (unexpected).
3. Type @.bug/file_hidden.txt → No results (unexpected).
4. Type @. → a list appears that includes .bug/file_hidden.txt (only visible after starting with a dot).
5. Type @visible_folder/file_showing.txt → Found (control check; expected).
6. Type @file_in_root.txt → Found (control check; expected).

<img width="432" height="274" alt="Image" src="https://github.com/user-attachments/assets/bc1fed23-d57e-4862-b153-5f64e12f7fb5" />
<img width="432" height="274" alt="Image" src="https://github.com/user-attachments/assets/d879dbcc-6c7f-4d4e-af3b-9a6d564f0649" />
<img width="432" height="274" alt="Image" src="https://github.com/user-attachments/assets/d2778452-157b-4538-9313-0e246a6be422" />

What is the expected behavior?

• Typing @file_hidden.txt should return .bug/file_hidden.txt based on filename match, even if its parent folder starts with a dot.
• Typing an explicit path like @.bug/file_hidden.txt should return that exact file.
• Results under dot-directories should not require the query to start with @.; starting with @. should be optional, not mandatory.
• (If there’s a hidden-files setting) honoring it consistently: when hidden files are included, both name and path queries must surface matches inside dot-directories.
• Ranking/format should be identical to non-hidden files (no special penalty or exclusion).

What do you see instead?

• @file_hidden.txt → No results (the file .bug/file_hidden.txt is not surfaced).
• @.bug/file_hidden.txt → No results (explicit path inside a dot-directory is ignored).
• @. → A list appears and does include .bug/file_hidden.txt (only visible after starting the query with a dot).
• @visible_folder/file_showing.txt → Found (works for non-hidden directories).
• @file_in_root.txt → Found (works for files in root).

So: files under dot-directories are excluded from both filename and explicit path queries unless the search string begins with @.. Reproducible 100%.

Additional information

• CLI WORKS: I tested the same workspace using the Codex CLI and the search works as expected there (@file_hidden.txt returns .bug/file_hidden.txt). The issue reproduces only in the VS Code extension UI. So it seems extension-specific rather than a backend/search-core issue.

I'm using the CLI version codex-cli 0.36.0

<img width="686" height="322" alt="Image" src="https://github.com/user-attachments/assets/16f02240-8787-4918-a0cc-540b22188288" />