unstructured

6ba8135b - fix: check ole storage content to differentiate filetypes (#3581)

fix: check ole storage content to differentiate filetypes (#3581) ### Summary Updates the file detection logic for OLE files to check the storage content of the file to more reliable differentiate between DOC, PPT, XLS and MSG files. This corrects a bug that caused file type detection to be incorrect in cases where the `filetype` library guessed and incorrect MIME type, such as `'application/vnd.ms-excel'` for a `.msg` file. As part of this work, the `"msg"` extra was removed because the `python-oxmsg` package is now a base dependency. ### Testing Using a test `.msg` file that returns `'application/vnd.ms-excel'` from `filetype.guess_mime`. ```python from unstructured.file_utils.filetype import detect_filetype filename = "test-file.msg" detect_filetype(filename=filename) # result should be FileType.MSG ```