* fix: Add application/octet-stream as a valid mimetype for docx uploads
* fix: Include application/octet-stream in frontend filter
fix: Add file size and file type guards
* Validate .docx extension in files with application/octet-stream mimetype
* refactor: Move MAXIMUM_IMPORT_SIZE to an optional environment config
fix: Add file size check on server too
Co-authored-by: Saumya Pandey <sp160899@gmail.com>