Examine source code of Zen Breathing Timer

{
  "manifest_version": 3,
  "name": "Zen Breathing Timer",
  "version": "1.0.0",
  "description": "Guided breathing exercises with meditation timer for relaxation and mindfulness",
  "permissions": [],
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "64": "icons/icon64.png",
      "128": "icons/icon128.png"
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "64": "icons/icon64.png",
    "128": "icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "zen-breathing-timer@example.com",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "content_security_policy": {
    "extension_pages": "script-src 'self'; object-src 'self'; img-src 'self' data:; style-src 'self';"
  }
}