Examine source code of Moonsun Toggle

{
  "manifest_version": 3,
  "name": "Moonsun Toggle",
  "version": "1.0.0",
  "description": "One-click toolbar toggle that cycles between your custom theme, Dark, and Light. Icon: Uicons by Flaticon.",
  "browser_specific_settings": {
    "gecko": {
      "id": "moonsun-toggle-v2@cutalion",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      },
      "strict_min_version": "115.0"
    }
  },
  "permissions": [
    "management",
    "storage",
    "theme"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_title": "Toggle theme",
    "default_icon": {
      "16": "icons/night-day-dark.svg",
      "32": "icons/night-day-dark.svg"
    },
    "theme_icons": [
      {
        "light": "icons/night-day-light.svg",
        "dark": "icons/night-day-dark.svg",
        "size": 16
      },
      {
        "light": "icons/night-day-light.svg",
        "dark": "icons/night-day-dark.svg",
        "size": 32
      }
    ]
  },
  "icons": {
    "48": "icons/night-day-dark.svg",
    "96": "icons/night-day-dark.svg"
  }
}