[BUG] /model command does not show model selection dialog, immediately outputs 'Kept model as X'

Description

The /model command does not present a model selection dialog. Instead, it immediately outputs "Kept model as glm-5:cloud" without showing any available models to choose from.

Steps to Reproduce

1. Configure ~/.claude/settings.json with custom models:

{
  "model": "glm-5:cloud",
  "availableModels": [
    "qwen3-coder-next:cloud",
    "qwen3.5:cloud",
    "kimi-k2.5:cloud",
    "glm-5:cloud",
    "minimax-m2.5:cloud",
    "minimax-m2.7:cloud"
  ]
}

1. Run /model command

Expected Behavior

A selection dialog should appear showing all 6 available models, allowing the user to choose a different model.

Actual Behavior

The command immediately outputs:

Kept model as glm-5:cloud

No selection dialog is shown, and the model cannot be changed.

Environment

• OS: macOS 26.3.1
• Kernel: Darwin 25.3.0 (ARM64)
• Shell: zsh
• Claude Code CLI

Additional Context

The models are configured with a :cloud suffix which may be non-standard/custom provider models. This might be related to why the selection UI is not working properly.

Workaround

Manually editing settings.json to change the "model" field, or using the --model CLI flag works as expected.