fix: conserver le type du métachamp lors de l'association manuelle

Sans le type, on envoyait toujours 'single_line_text_field' à Shopify,
causant une erreur quand le métachamp existant est de type number_decimal.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/components/creation/MetafieldResolver.tsx

@@ -174,7 +174,7 @@ export function MetafieldResolver({ specificColumns, onResolved }: Props) {
                                 <button
                                   key={d.id}
                                   type="button"
-                                  onMouseDown={() => { updateResolution(col, { existingDefinitionId: d.id, key: d.key, namespace: d.namespace }); setOpenDropdown(null) }}
+                                  onMouseDown={() => { updateResolution(col, { existingDefinitionId: d.id, key: d.key, namespace: d.namespace, type: d.type }); setOpenDropdown(null) }}
                                   className="w-full text-left px-3 py-1.5 text-xs text-white hover:bg-slate-600 flex justify-between gap-2"
                                 >
                                   <span>{d.name}</span>