Extract receipt and generate expense report document

Combines receipt extraction and document generation in a single call.

1. Extracts data from the uploaded receipt image using AI
2. Generates a formatted expense report PDF or DOCX using the extracted data

Optionally provide a template name to use a custom expense report template. Without a template, a clean default HTML-based expense report is generated.

This endpoint consumes AI credits for the extraction step plus standard credits for the document generation.