Examine source code of Chat Timeline Map

{
  "manifest_version": 3,
  "name": "Chat Timeline Map",
  "version": "1.1.0",
  "description": "Interactive Timeline Map for ChatGPT, Gemini, and Claude. Works on Chrome & Firefox.",
  "permissions": [
    "storage",
    "activeTab",
    "scripting"
  ],
  "host_permissions": [
    "https://chatgpt.com/*",
    "https://gemini.google.com/*",
    "https://claude.ai/*"
  ],
  "action": {
    "default_popup": "popup.html",
    "default_title": "Chat Timeline Settings"
  },
  "background": {
    "service_worker": "background.js",
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "https://chatgpt.com/*",
        "https://gemini.google.com/*",
        "https://claude.ai/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "styles.css"
      ],
      "run_at": "document_idle"
    }
  ],
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "chat-timeline-map@extension",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}