Plugin format specific paths

[kmturley]

Background

Currently Open Audio Stack has one root plugin directory (per system):

• Linux platform $HOME/usr/local/lib/$format
• Mac platform $HOME/Library/Audio/Plug-ins/$format
• Windows platform C:\Program Files (x86)\Common Files\$format

Then a subdirectory is appended for the format (Clap, Components, Lv2, VST, VST3)

Current spec is here:
https://github.com/open-audio-stack/open-audio-stack-core/blob/main/specification.md#app-directory

Current logic in code is here:
https://github.com/open-audio-stack/open-audio-stack-core/blob/main/src/helpers/file.ts#L138

Problem

Issues is that plugin installation directories are actually different per format. So although this works for 80% of cases, it won't always work on every system for every format.

Solution

Implement plugin format specific installation paths:

Clap: https://github.com/free-audio/clap/blob/29ffcc273be7c7c651f6c9953b99e69700e2387a/include/clap/entry.h#L12
Lv2: https://lv2plug.in/pages/filesystem-hierarchy-standard.html
VST: https://helpcenter.steinberg.de/hc/en-us/articles/115000177084-VST-plug-in-locations-on-Windows

[atsushieno]

For the normative reference, VST3 file paths (including Linux paths) are described at: https://steinbergmedia.github.io/vst3_dev_portal/pages/Technical+Documentation/Locations+Format/Plugin+Locations.html