Examine source code of Offline 2FA Generator

{
  "manifest_version": 2,
  "name": "Offline 2FA Generator",
  "version": "1.1.0.2",
  "description": "Offline TOTP code generator for two-factor authentication",
  "homepage_url": "https://agentie.marketing",
  "author": "Selmark Advertising <george@agentie.marketing>",
  "developer": {
    "name": "Selmark Advertising",
    "url": "https://agentie.marketing"
  },
  "code_assistance": "Claude (Anthropic)",
  "browser_specific_settings": {
    "gecko": {
      "id": "offline-2fa-generator@agentie.marketing",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": [],
        "collectsTelemetry": false
      }
    }
  },
  "permissions": [
    "storage",
    "activeTab",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "js/totp_selmark_2fa.js",
      "js/background_selmark_2fa.js"
    ],
    "persistent": false
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "js/content_selmark_2fa.js"
      ],
      "css": [],
      "run_at": "document_end"
    }
  ],
  "browser_action": {
    "default_popup": "popup_selmark_2fa.html",
    "default_title": "Offline 2FA Generator",
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png",
      "128": "icons/icon-128.png"
    }
  },
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "content_security_policy": "script-src 'self'; object-src 'self';"
}