Examine source code of Focus Mode

{
  "manifest_version": 3,
  "name": "Focus Mode",
  "version": "1.0.0",
  "description": "A Pomodoro focus timer with site blocking and daily productivity stats.",
  "permissions": [
    "storage",
    "alarms",
    "notifications",
    "declarativeNetRequest",
    "declarativeNetRequestWithHostAccess"
  ],
  "host_permissions": [
    "<all_urls>"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "action": {
    "default_popup": "popup.html",
    "default_title": "Focus Mode",
    "default_icon": {
      "16": "icons/icon16.png",
      "48": "icons/icon48.png",
      "128": "icons/icon128.png"
    }
  },
  "icons": {
    "16": "icons/icon16.png",
    "48": "icons/icon48.png",
    "128": "icons/icon128.png"
  },
  "options_page": "options.html",
  "declarative_net_request": {
    "rule_resources": [
      {
        "id": "base_rules",
        "enabled": true,
        "path": "rules.json"
      }
    ]
  },
  "web_accessible_resources": [
    {
      "resources": [
        "blocked.html",
        "blocked.js"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{d8784b50-6406-4eb0-b9b0-c44301f6d154}",
      "strict_min_version": "142.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  }
}