refactor(dashboard): commerce/variants to setup-style + signals (#1838)

Was the v1 `<script>` + `setup()` shape, including a wonky
`return { ... }` after a missing closing brace on the addVariantType
push call (`variantTypes.push({...} closeAddModal()`). Repaired the
broken Vue ternary on the Status badge (`class="… : ? 'bg-green-100' …"`).

Inline option-builder (newOptions array + newOption text input + add /
remove handlers) preserved — newOptions is a `state<string[]>` so the
list re-renders as the user adds entries.

@foreach iteration on options uses `as option, index` per stx convention;
removeOption(index) called from the close button of each chip.

Author: glennmichael123