fix: correct argparse long options and logger TypeError

[Famous077]

Fixes #139

Changes:

• Fixed -path and -url to --path and --url in scripts/upload.py so argparse correctly treats them as long options
• Replaced string concatenation "export failed: " + ex with logger.error("export failed: %s", ex) in murakami/exporter.py to prevent TypeError when ex is not a string

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This change is 

[Famous077]

This PR fixes issue #139 corrected -path/-url to --path/--url in upload.py and replaced unsafe string concatenation in logger.error() with %s formatting in exporter.py. Both files verified with py_compile.

Happy to make any updates based on your feedback. Thank you

[Famous077]

The test stage passes on Python 3.6 and 3.7.
The deploy stage failure is unrelated to this PR ,
it requires PyPI credentials that are not available in fork PR builds.