Run a Shopify Admin GraphQL bulk mutation to update variant prices across a large catalog using stagedUploadsCreate and bulkOperationRunMutation

Verified steps

1. Prepare a JSONL file where each line is a JSON object representing one productVariantUpdate input: { "input": { "id": "gid://shopify/ProductVariant/...", "price": "19.99" } }
2. Call stagedUploadsCreate Admin GraphQL mutation with input specifying resource: BULK_MUTATION_VARIABLES, filename, mimeType: 'text/jsonl', and httpMethod: POST; the response returns a staged upload target with url and parameters
3. Upload the JSONL file to the staged upload URL using a multipart form POST with the parameters from the previous step; confirm a 200 response before proceeding
4. Call bulkOperationRunMutation with the mutation string (productVariantUpdate with $input variable) and the stagedUploadPath from the staged upload response to start the bulk operation
5. Poll currentBulkOperation for status; when COMPLETED retrieve the url (results JSONL) and optionally partialDataUrl for any partial results; parse the results to identify any lines that returned userErrors
6. Log and retry failed lines individually using standard single mutations; bulk mutations do not retry on partial failure — your app is responsible for handling line-level errors from the results JSONL