Examine source code of LinguaLens

{
  "manifest_version": 3,
  "name": "LinguaLens",
  "description": "Vocabulary reinforcement while you read. LinguaLens swaps studied words inline as you browse. Only snippets leave your browser.",
  "version": "1.0.4",
  "icons": {
    "16": "icon/16.png",
    "32": "icon/32.png",
    "48": "icon/48.png",
    "96": "icon/96.png",
    "128": "icon/128.png"
  },
  "permissions": [
    "storage",
    "unlimitedStorage",
    "alarms",
    "notifications",
    "cookies",
    "tabs"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "content_security_policy": {
    "extension_pages": "script-src 'self'; object-src 'self'; connect-src 'self' https://api.lingualens.app https://*.ingest.us.sentry.io http://127.0.0.1:8765 http://localhost:8765"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "lingualens@lingualens.app",
      "strict_min_version": "109.0"
    }
  },
  "commands": {
    "toggle-replacements": {
      "suggested_key": {
        "default": "Alt+Shift+L"
      },
      "description": "Toggle LinguaLens replacements on/off"
    },
    "open-settings": {
      "suggested_key": {
        "default": "Alt+Shift+S"
      },
      "description": "Open LinguaLens settings"
    }
  },
  "background": {
    "type": "module",
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_title": "LinguaLens",
    "default_popup": "popup.html"
  },
  "options_ui": {
    "open_in_tab": true,
    "page": "options.html"
  },
  "content_scripts": [
    {
      "matches": [
        "https://lingualens.app/extension/auth-callback*"
      ],
      "run_at": "document_idle",
      "js": [
        "content-scripts/auth-callback.js"
      ]
    },
    {
      "matches": [
        "https://lingualens.app/billing/success*"
      ],
      "run_at": "document_start",
      "js": [
        "content-scripts/checkout-success.js"
      ]
    },
    {
      "matches": [
        "<all_urls>"
      ],
      "run_at": "document_idle",
      "js": [
        "content-scripts/content.js"
      ],
      "world": "ISOLATED"
    },
    {
      "matches": [
        "https://lingualens.app/extension/onboarding-callback*"
      ],
      "run_at": "document_idle",
      "js": [
        "content-scripts/onboarding-callback.js"
      ]
    },
    {
      "matches": [
        "https://lingualens.app/*",
        "https://www.lingualens.app/*"
      ],
      "run_at": "document_start",
      "js": [
        "content-scripts/webapp-marker.js"
      ]
    },
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "run_at": "document_idle",
      "js": [
        "content-scripts/youtube-main-world.js"
      ],
      "world": "MAIN"
    },
    {
      "matches": [
        "*://*.youtube.com/*"
      ],
      "run_at": "document_idle",
      "js": [
        "content-scripts/youtube.js"
      ],
      "world": "ISOLATED"
    }
  ]
}