Examine source code of Circadian

{
  "icons": {
    "16": "icon16.plasmo.2577fc03.png",
    "32": "icon32.plasmo.d583dc1e.png",
    "48": "icon48.plasmo.e0fcfb1d.png",
    "64": "icon64.plasmo.e6259081.png",
    "128": "icon128.plasmo.96a1ede9.png"
  },
  "manifest_version": 3,
  "action": {
    "default_icon": {
      "16": "icon16.plasmo.2577fc03.png",
      "32": "icon32.plasmo.d583dc1e.png",
      "48": "icon48.plasmo.e0fcfb1d.png",
      "64": "icon64.plasmo.e6259081.png",
      "128": "icon128.plasmo.96a1ede9.png"
    },
    "default_popup": "popup.html"
  },
  "version": "1.0.4",
  "author": "Pas",
  "name": "Circadian",
  "description": "A browser extension that tints pages by time of day (daytime, sunset, bedtime).",
  "background": {
    "scripts": [
      "static/background/index.js"
    ]
  },
  "permissions": [
    "storage",
    "activeTab"
  ],
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "circadian-filter.0e4861a9.js"
      ],
      "all_frames": true,
      "css": []
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "{6f4f2a20-9f6c-4a87-9cf5-5d4e9a3c1b2e}",
      "strict_min_version": "109.0"
    }
  },
  "host_permissions": [
    "https://*/*"
  ]
}