Add Microbiome plugin

[kmturley]

Summary

• Adds Microbiome (dsmaugy/microbiome), a delay-based audio effects plugin
• macOS: AU, universal binary (arm64 + x64), verified via zip inspection + lipo — fetch.ts had guessed VST3+LV2 for this AU-only zip
• Linux: separate VST3-only and LV2-only zips (x64), verified — fetch.ts had merged both formats into each zip's contains list incorrectly
• Windows: VST3 (x64)
• GPL-3.0 licensed

Part of the OpenAudio README batch: https://github.com/webprofusion/OpenAudio/blob/master/README.md

[github-actions]

VirusTotal Report:

• dsmaugy/microbiome/1.0.0/Microbiome_Linux_x86_LV2_v1.0.0.zip
• dsmaugy/microbiome/1.0.0/Microbiome_Linux_x86_VST3_v1.0.0.zip
• dsmaugy/microbiome/1.0.0/Microbiome_MacOS_AU_v1.0.0.zip
• dsmaugy/microbiome/1.0.0/Microbiome_Win_VST3_v1.0.0.zip

[github-actions]

Destination urls:
Registry: https://open-audio-stack.github.io/open-audio-stack-registry/plugins/dsmaugy/microbiome
Site: https://studiorack.github.io/studiorack-site/plugins/dsmaugy/microbiome

[github-actions]

Plugin author notification:

@dsmaugy — your plugin has been submitted to the Open Audio Stack registry. Please review this PR and let us know if the metadata (name, description, tags, files) is correct. To see a full list of all currently added plugins, click here.

[kmturley]

VirusTotal flagged these binaries:

https://www.virustotal.com/gui/file/f7c4f78e2ef68a34b5b54e8a56509b59a2e9176c0a3a07ce006d14434dea6796?nocache=1
https://www.virustotal.com/gui/file/6b5def3f67657d8ab316703ec631f90176342ccfd7d0ffca892414cb8ac7fbff?nocache=1