TUI skill picker uses display_name casing, causing explicit-only skill invocation to fail

What version of Codex CLI is running?

codex-cli 0.149.1

Platform

Arch Linux, kernel 7.1.9, x86_64

Originator

codex-tui, source cli

What issue are you seeing?

Selecting an explicit-only skill from the $ picker produces a mention using the
skill's title-cased interface.display_name. The canonical skill name is lowercase.

The picker-generated mention fails. Manually typing the canonical lowercase name
succeeds.

The valid skill appears in the picker, but selection immediately produces:

The Wayfinder skill is not available in this session.

Skill metadata

SKILL.md:

---
name: wayfinder
description: Plan a large effort as a shared map of decision tickets.
disable-model-invocation: true
---

agents/openai.yaml:

interface:
  display_name: "Wayfinder"
  short_description: "Map a large effort as decision tickets"
policy:
  allow_implicit_invocation: false

The skill is installed at:

~/.agents/skills/wayfinder/SKILL.md

There is no skills.config entry disabling it.

Reproduction

1. Start a fresh Codex TUI session.
2. Open the $ skill picker.
3. Select Wayfinder.
4. Submit $Wayfinder #1.
5. Observe that Codex reports the skill unavailable.
6. Start another fresh session.
7. Manually type $wayfinder #1.
8. Observe that Codex loads and follows the skill.

Redacted rollout evidence

Picker invocation:

session_meta:
  cli_version: 0.149.1
  originator: codex-tui
  source: cli

user:
  $Wayfinder #1

assistant:
  The Wayfinder skill is not available in this session.

Manual invocation:

session_meta:
  cli_version: 0.149.1
  originator: codex-tui
  source: cli

user:
  $wayfinder #1

assistant:
  I'm using Wayfinder to load map #1...

I reproduced the picker failure in at least four fresh sessions.

Suspected cause

The picker appears to submit interface.display_name as a plain $name token
instead of submitting the canonical skill identity or a structured
UserInput::Skill.

Plain mention selection currently calls:

mentions.contains_plain_name(skill.name.as_str())

contains_plain_name performs an exact set lookup. Therefore $Wayfinder does
not match the canonical name wayfinder.

Expected behavior

Selecting a skill from the picker should invoke that exact skill regardless of
display-name capitalization.

The picker could submit a structured UserInput::Skill containing the canonical
path, emit the canonical name, or make plain-name comparison case-insensitive.

Related issues

• #23454
• #40600

Start by tracing the TUI skill picker’s selection path and the plain-name handling through mentions.contains_plain_name(skill.name.as_str()). Reproduce the $Wayfinder failure and $wayfinder success, then verify that selecting a title-cased display name invokes the canonical wayfinder skill without breaking explicit-only behavior.