📌 Summary

This PR extends the OCR/Extraction service to support multiple additional file types beyond the currently supported formats (PDF, DOCX, PPTX).

✅ Added File Type Support

• .DOC (Microsoft Word 97–2003)
• .XLS, .XLSX (Microsoft Excel formats)
• .ODT, .ODS, .ODP (OpenDocument formats)
• .TXT (Plain text)
• .RTF (Rich Text Format)
• .EPUB (eBook format)

Fixes #3 /claim #3