Examine source code of Pockab — Language Capture

{
  "manifest_version": 3,
  "name": "Pockab — Language Capture",
  "version": "0.1.16",
  "description": "Capture vocabulary & YouTube subtitles to your Pockab vocabulary app (offline-first).",
  "permissions": [
    "storage",
    "identity",
    "alarms"
  ],
  "host_permissions": [
    "http://localhost:3001/*",
    "http://127.0.0.1:3001/*",
    "https://pockab.flazhost.com/*"
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{760c432e-3fde-4bcd-ab1a-73e3ec5ad54a}",
      "strict_min_version": "115.0"
    }
  },
  "background": {
    "scripts": [
      "background.js"
    ],
    "type": "module"
  },
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "action": {
    "default_title": "Pockab",
    "default_popup": "popup/popup.html",
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png",
      "128": "icons/icon-128.png"
    }
  },
  "content_scripts": [
    {
      "matches": [
        "https://*.youtube.com/*",
        "https://pockab.flazhost.com/*",
        "http://localhost:3001/*",
        "http://127.0.0.1:3001/*"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ]
}