Examine source code of Sourcerer — source management for journalists

{
  "manifest_version": 3,
  "name": "Sourcerer – Journalist Contact Management",
  "version": "1.1.2",
  "description": "Capture screenshots, save selected text as contact fields, and add new contacts to Sourcerer — the encrypted source management app.",
  "browser_specific_settings": {
    "gecko": {
      "id": "sourcerer@sourcerer.app",
      "strict_min_version": "109.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    }
  },
  "permissions": [
    "storage",
    "activeTab",
    "scripting",
    "contextMenus"
  ],
  "host_permissions": [
    "http://127.0.0.1:27371/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "icons": {
    "16": "icons/icon-16.png",
    "32": "icons/icon-32.png",
    "48": "icons/icon-48.png",
    "128": "icons/icon-128.png"
  },
  "action": {
    "default_popup": "popup.html",
    "default_title": "Save to Sourcerer",
    "default_icon": {
      "16": "icons/icon-16.png",
      "32": "icons/icon-32.png",
      "48": "icons/icon-48.png",
      "128": "icons/icon-128.png"
    }
  }
}