MuGen 3.0.0 is a major desktop update

We focused on making song generation easier to use, and easier to understand

New interface:

• Rebuilt the app around task-focused tabs: Compose, Arrange, Mixer, Results, and Settings.

• Added a clearer Compose flow for song setup, progressions, output, and generation.

• Added dedicated Arrange and Mixer screens for track selection, instruments, playback, MIDI output, and generated-song review.

• Added a Results view with generated-song actions instead of exposing raw file paths.

• Improved tooltips, toasts, table views, progression rows, and track action handling.

• Refined styling, layout, spacing, and control grouping across the app.

Localization:

• Added expanded language support and locale handling.

• Added/updated translations for English, French, Italian, German, Spanish, Japanese, Portuguese, Russian, and Simplified Chinese.

• Bundled additional Japanese and Simplified Chinese fonts for better text rendering.

Fixes and polish:

• Improved MIDI/playback shutdown behavior.

• Updated the generated manual.