Examine source code of Gmail Headers Beautifier

{
  "manifest_version": 3,
  "name": "Gmail Headers Beautifier",
  "version": "1.0.6",
  "description": "Enhance Gmail's 'Show Original' view with intelligent header parsing and formatting. Compatible with Chrome, Edge, and Firefox.",
  "default_locale": "en",
  "permissions": [
    "storage",
    "activeTab"
  ],
  "host_permissions": [
    "https://mail.google.com/*"
  ],
  "content_scripts": [
    {
      "matches": [
        "https://mail.google.com/*"
      ],
      "js": [
        "browser-polyfill.js",
        "esp/utils/ip_utils.js",
        "esp_identifier.js",
        "esp_identifier_fixed.js",
        "authentication-analyzer.js",
        "content-script.js"
      ],
      "css": [
        "styles.css"
      ],
      "run_at": "document_end"
    }
  ],
  "background": {
    "scripts": [
      "browser-polyfill.js",
      "background.js"
    ],
    "persistent": false
  },
  "action": {
    "default_popup": "popup.html",
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "options_page": "options.html",
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "web_accessible_resources": [
    {
      "resources": [
        "styles.css",
        "authentication-analyzer.js",
        "esp_fingerprints.json",
        "esp_identifier.js",
        "esp_identifier_fixed.js",
        "esp/utils/ip_utils.js",
        "i18n.js",
        "_locales/en/messages.json",
        "_locales/it/messages.json",
        "_locales/es/messages.json",
        "_locales/fr/messages.json",
        "_locales/de/messages.json",
        "_locales/pt/messages.json"
      ],
      "matches": [
        "https://mail.google.com/*",
        "<all_urls>"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "gmail-headers-beautifier@topdeliverability.com",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "purposes": [],
        "required": [
          "none"
        ]
      }
    }
  }
}