Examine source code of GmailRatio Legacy

{
  "manifest_version": 2,
  "name": "GmailRatio Legacy",
  "version": "1.14.9",
  "description": "RatioWorks Gmail compatibility and safer cleanup with reliable Inbox single/bulk removal, adaptive compact controls, sender grouping, protected business senders, confirmed Spam/Trash deletion, independent RatioWorks themes, and local-only settings.",
  "icons": {
    "48": "icons/icon.svg",
    "96": "icons/icon.svg"
  },
  "permissions": [
    "storage",
    "webRequest",
    "webRequestBlocking",
    "https://mail.google.com/*",
    "https://accounts.google.com/*"
  ],
  "background": {
    "scripts": [
      "background.js"
    ]
  },
  "browser_action": {
    "default_title": "GmailRatio Legacy · RatioWorks",
    "default_icon": "icons/icon.svg"
  },
  "content_scripts": [
    {
      "matches": [
        "https://mail.google.com/*",
        "https://accounts.google.com/*"
      ],
      "js": [
        "identity-shim.js"
      ],
      "run_at": "document_start"
    },
    {
      "matches": [
        "https://mail.google.com/*"
      ],
      "js": [
        "content.js"
      ],
      "css": [
        "gmail-lite.css",
        "gmail-cleanup.css"
      ],
      "run_at": "document_start"
    }
  ],
  "browser_specific_settings": {
    "gecko": {
      "id": "gmailratio-legacy@ratioworks",
      "strict_min_version": "140.0",
      "data_collection_permissions": {
        "required": [
          "none"
        ]
      }
    },
    "gecko_android": {
      "strict_min_version": "142.0"
    }
  },
  "author": "Constantino Arango / RatioWorks"
}