Help text displays incorrect short option for `--provider`

[webmatze]

The --help output for open-codex incorrectly displays the short option for --provider.

Steps to reproduce:

1. Run open-codex --help in your terminal.
2. Observe the output.

Expected behavior:

The help text should display -p as the short option for --provider.

Actual behavior:

The help text displays -m as the short option for both --provider and --model, which is incorrect and causes confusion.

open-codex --help

  Usage
    $ codex [options] <prompt>
    $ codex completion <bash|zsh|fish>

  Options
    -h, --help                 Show usage and exit
    -m  --provider <provider>  Provider to use for completions (default: openai, options: openai, gemini, openrouter)
    -m, --model <model>        Model to use for completions (default: o4-mini)
    -i, --image <path>         Path(s) to image files to include as input
    ...

Proposed Solution:

Change the short option displayed in the help text for --provider from -m to -p.

Environment:

• open-codex version: 0.1.30
• OS: macOS
• Shell: zsh