v0.9.4

• Fixed process abort (uncatchable std::terminate → SIGABRT) in image_meta_extract() when an
  image carries a metadata value that exiv2 cannot convert to UTF-8, e.g. an EXIF UserComment
  declared UNICODE with an invalid UTF-16 payload as written by some early-2000s digital cameras;
  undecodable fields are now skipped with a warning instead of crashing the process
• Fixed CI: EPUB raw-name zip test fixture broke on Python 3.13/3.14 (CPython's zip-spoofing
  hardening now stamps the UTF-8 filename flag during writing; the fixture clears it explicitly)