Examine source code of Read That (Pocket TTS)

{
  "manifest_version": 3,
  "name": "Read That (Pocket TTS)",
  "version": "1.0.0",
  "description": "Right-click selected text → send to Pocket TTS and play with a floating mini-player.",
  "permissions": [
    "contextMenus",
    "storage",
    "scripting",
    "activeTab"
  ],
  "host_permissions": [
    "http://localhost/*",
    "http://127.0.0.1/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "pocket-tts-read-that@example.com",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "options_ui": {
    "page": "options.html",
    "open_in_tab": true
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_idle"
    }
  ]
}