Examine source code of Kanban Card User Filter

{
  "manifest_version": 3,
  "name": "Kanban Card User Filter",
  "version": "1",
  "description": "Filter Kanban cards by assignee on Basecamp board pages with configurable tags.",
  "permissions": [
    "storage"
  ],
  "action": {
    "default_popup": "popup.html",
    "default_title": "Kanban Filter Settings"
  },
  "content_scripts": [
    {
      "matches": [
        "https://3.basecamp.com/*"
      ],
      "js": [
        "scripts/browser-compat.js",
        "scripts/config.js",
        "scripts/utils.js",
        "scripts/parser.js",
        "scripts/data.js",
        "scripts/ui-renderer.js",
        "scripts/filter.js",
        "scripts/contents.js"
      ],
      "css": [
        "styles.css"
      ],
      "all_frames": true
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "kanban-card-user-filter@basecamp",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}