Examine source code of WASD Scroller

{
  "manifest_version": 2,
  "name": "WASD Scroller",
  "version": "1.22",
  "description": "Scroll pages using W, A, S, D keys with auto-scroll mode, arrow key support, and customizable bindings.",
  "permissions": [
    "<all_urls>",
    "storage"
  ],
  "icons": {
    "48": "icons/wasd-48.png",
    "96": "icons/wasd-96.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{9b547e46-7007-4e0c-895a-0488204535b8}",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "app.js"
      ],
      "all_frames": true
    }
  ],
  "background": {
    "scripts": [
      "background_scripts/background.js"
    ]
  },
  "browser_action": {
    "default_popup": "popup.html",
    "default_icon": {
      "48": "icons/wasd-48.png"
    }
  },
  "content_security_policy": "script-src 'self'; object-src 'self';"
}