Examine source code of Per-Tab Audio Filter

{
  "manifest_version": 2,
  "name": "Per-Tab Audio Filter",
  "version": "1.0",
  "description": "Apply per-tab audio filters (bass, treble, vocal, lo-fi).",
  "icons": {
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "browser_action": {
    "default_title": "Audio Filter",
    "default_popup": "popup.html"
  },
  "permissions": [
    "activeTab",
    "storage",
    "tabs",
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ],
    "persistent": false
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "per-tab-audio-filter@example.com",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ],
        "optional": []
      }
    }
  }
}