Examine source code of Browser Media Controls

{
  "manifest_version": 3,
  "name": "Media Controls",
  "version": "1.0.2",
  "description": "Centralized browser hub to control audio/video playback, speed, volume, and track navigation across open tabs.",
  "homepage_url": "https://github.com/shashaank57/media-controls",
  "permissions": [
    "tabs",
    "activeTab",
    "storage",
    "scripting"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "content.css"
      ],
      "run_at": "document_start",
      "all_frames": true
    }
  ],
  "icons": {
    "16": "icons/icon16.png",
    "32": "icons/icon32.png",
    "48": "icons/icon48.png",
    "64": "icons/icon64.png",
    "128": "icons/icon128.png"
  },
  "action": {
    "default_popup": "popup/popup.html",
    "default_title": "Media Controls",
    "default_icon": {
      "16": "icons/icon16.png",
      "32": "icons/icon32.png",
      "48": "icons/icon48.png",
      "64": "icons/icon64.png",
      "128": "icons/icon128.png"
    }
  },
  "commands": {
    "toggle-play-pause": {
      "suggested_key": {
        "default": "Alt+Shift+P",
        "mac": "Alt+Shift+P"
      },
      "description": "Play or pause active media across tabs"
    },
    "speed-up": {
      "suggested_key": {
        "default": "Alt+Shift+Right",
        "mac": "Alt+Shift+Right"
      },
      "description": "Increase playback speed (+0.25x)"
    },
    "speed-down": {
      "suggested_key": {
        "default": "Alt+Shift+Left",
        "mac": "Alt+Shift+Left"
      },
      "description": "Decrease playback speed (-0.25x)"
    }
  },
  "web_accessible_resources": [
    {
      "resources": [
        "content.css",
        "icons/*",
        "injected-hooks.js"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "global-media-controller@extension.local",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}