Render the option(⌥) sigil for alt on macos

[rak-phillip]

Summary

This renders the option(⌥) sigil for alt on macos.

Occurred changes and/or fixed issues

• Render the option(⌥) sigil for alt on macos

Technical notes summary

alt should properly map to the option key, although it is not explicitly called out in the vue-shortkey docs: https://github.com/fgr-araujo/vue-shortkey?tab=readme-ov-file#key-list

Areas or cases that should be tested

This can be tested along with rancher/rancher-ai-ui#54

Areas which could experience regressions

Existing shortcuts that use the alt key on macos will now render the sigil.

Screenshot/Video

Checklist

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