Examine source code of YouTube Embed Redirect

{
  "manifest_version": 3,
  "name": "YouTube Embed Redirect",
  "short_name": "yt-embed-redirect",
  "version": "1.0.0",
  "description": "Redirects YouTube watch/shorts pages to the privacy-friendly embed player and injects a Referer header so the embed loads without error 152/153.",
  "author": "migtorr",
  "icons": {
    "48": "assets/icon.svg",
    "96": "assets/icon.svg"
  },
  "permissions": [
    "storage",
    "webRequest",
    "webRequestBlocking"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "*://www.youtube-nocookie.com/embed/*",
        "*://www.youtube.com/embed/*"
      ],
      "js": [
        "cs-embed.js"
      ],
      "run_at": "document_idle",
      "all_frames": false
    },
    {
      "matches": [
        "*://www.youtube.com/watch*"
      ],
      "js": [
        "cs-watch.js"
      ],
      "run_at": "document_start",
      "all_frames": false
    }
  ],
  "action": {
    "default_popup": "popup.html",
    "default_title": "YouTube Embed Redirect",
    "default_icon": {
      "48": "assets/icon.svg"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "yt-embed-redirect@migtorr",
      "strict_min_version": "128.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}