Codex TUI treats scoped npm package strings as @ file mentions and blocks normal Enter submit

What version of Codex CLI is running?

codex-cli 0.103.0

What subscription do you have?

Enterprise

Which model were you using?

gpt-5.3-codex

What platform is your computer?

Darwin 25.3.0 arm64 arm

What terminal emulator and version are you using (if applicable)?

iTerm2

What issue are you seeing?

##Observed:
Reproducible before fix commit 80791c29 (authored on February 18, 2026)

##Summary:
When a prompt contains a scoped npm package with a version suffix (example: @kaeawc/auto-mobile@latest), the composer incorrectly activates @ file-search behavior instead of treating the token as plain text.

Actual Result:

TUI freezes and Enter does not behave like a normal submit for that prompt.

Impact:

Users pasting common npm commands with scoped packages can’t reliably submit prompts, which interrupts normal chat flow.

What steps can reproduce the bug?

1. Open Codex TUI and focus the chat composer.
2. Type: npx -y @kaeawc/auto-mobile@latest
3. Press Enter.

What is the expected behavior?

Prompt is submitted as typed.

Additional information

Likely Root Cause:

Mention parsing accepts @-prefixed tokens even when the remainder includes a second @ (package version syntax), causing false-positive mention detection.

Additional context:

I did fix this on my own branch via codex 5.3

https://github.com/simonsickle/codex/tree/simonsickle/fix-file-search-tui

The fix seemed reasonably small