Import warnings for category metafields

Shopify’s category metafields only apply to products in specific categories. Previously, importing a product with a category metafield that didn’t match would fail the entire import. Now Altera skips incompatible metafields and imports the rest of the product successfully.

🔧 Improvements

• Category metafield mismatch – when a metafield like shopify.gender doesn’t apply to a product’s category, Altera skips it and continues instead of failing.
• Unresolved references – metafields referencing metaobjects or files that don’t exist are now skipped with a warning rather than blocking the import.
• Warning details – skipped metafields appear in import results with the specific field and reason (e.g., “Skipped shopify.gender: not valid for this product category”).