LJmp3converter 1.0.5

Changes in this version:

• Fully removed shiny dependency and replaced it with rstudioapi and utils for file selection.
• Added required web service URL (<https://github.com/BtbN/FFmpeg-Builds/releases/download/latest/ffmpeg-master-latest-win64-gpl.zip>) in DESCRIPTION.
• Fixed documentation issues:
  • Added @return to exported functions (run_converter_app.R, download_ffmpeg.R).
  • Ensured compliance with CRAN policies for .Rd files.
• Performance improvements:
  • Replaced installed.packages() with requireNamespace().
  • Removed install.packages() calls inside functions.
• Ensured on.exit() restores options after changes (options(timeout = 3000)).
• Updated README to clarify ‘FFmpeg’ download process.
• Fixed CRAN test failure by skipping download_ffmpeg() test on CRAN.
  
• Improved test handling for non-interactive environments.
  
• Ensured package compliance with CRAN’s testing policies.