Examine source code of Color Contrast Checker

{
  "manifest_version": 3,
  "name": "Color Contrast Checker",
  "short_name": "Contrast Check",
  "version": "1.0.0",
  "description": "Check WCAG color contrast ratios, pick colors from any page, and save accessible pairs.",
  "browser_specific_settings": {
    "gecko": {
      "id": "color-contrast-checker@paintcolorconsultants.com",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "action": {
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png"
    },
    "default_title": "Open Contrast Checker"
  },
  "permissions": [
    "activeTab",
    "scripting",
    "storage"
  ],
  "background": {
    "service_worker": "background/service-worker.js",
    "scripts": [
      "background/service-worker.js"
    ]
  },
  "web_accessible_resources": [
    {
      "resources": [
        "widget/*"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ]
}