Examine source code of Smart Email Writer

{
  "name": "Smart Email Writer",
  "description": "AI-powered email reply generator for Gmail using Google Gemini AI",
  "version": "1.0",
  "manifest_version": 2,
  "browser_specific_settings": {
    "gecko": {
      "id": "smart-email-writer@kshitiz-access.github.io",
      "data_collection_permissions": {
        "required": [
          "websiteContent"
        ],
        "optional": [
          "technicalAndInteraction"
        ]
      }
    }
  },
  "permissions": [
    "activeTab",
    "storage",
    "https://smart-email-writer-sb-production.up.railway.app/*",
    "*://mail.google.com/*"
  ],
  "content_scripts": [
    {
      "js": [
        "content.js"
      ],
      "matches": [
        "*://mail.google.com/*"
      ],
      "css": [
        "content.css"
      ],
      "run_at": "document_end"
    }
  ],
  "web_accessible_resources": [
    "icons/*"
  ],
  "browser_action": {
    "default_title": "Smart Email Writer"
  }
}