Examine source code of Music Spectrum

{
  "manifest_version": 3,
  "name": "Music Spectrum",
  "short_name": "YTMS",
  "description": "Audio visualizer for YouTube and YT Music with musical notes.",
  "version": "12.0.0",
  "icons": {
    "16": "modules/@mfcc64/ytms-assets@1.0.0/icon-16.png",
    "24": "modules/@mfcc64/ytms-assets@1.0.0/icon-24.png",
    "32": "modules/@mfcc64/ytms-assets@1.0.0/icon-32.png",
    "48": "modules/@mfcc64/ytms-assets@1.0.0/icon-48.png",
    "64": "modules/@mfcc64/ytms-assets@1.0.0/icon-64.png",
    "128": "modules/@mfcc64/ytms-assets@1.0.0/icon-128.png"
  },
  "action": {},
  "browser_specific_settings": {
    "gecko": {
      "id": "{55cffb20-09ff-11f0-9cd2-0242ac120002}"
    },
    "gecko_android": {}
  },
  "web_accessible_resources": [
    {
      "matches": [
        "https://www.youtube.com/*",
        "https://music.youtube.com/*"
      ],
      "resources": [
        "*.png",
        "/modules/*.mjs",
        "/modules/*.wasm"
      ]
    }
  ],
  "content_scripts": [
    {
      "run_at": "document_end",
      "js": [
        "wrapper.js"
      ],
      "matches": [
        "https://www.youtube.com/*",
        "https://music.youtube.com/*"
      ]
    }
  ],
  "content_security_policy": {
    "extension_pages": "default-src 'none'; script-src 'self'; style-src 'self'; img-src 'self';"
  }
}