Chrome extension structure: A minimal one can just use: manifest and background
extension-folder/
├── manifest.json # REQUIRED: Metadata and permissions
├── background.js # Background script or service worker (persistent/ephemeral logic)
├── content.js # Injected into webpages
├── popup.html # (Optional) UI when clicking the extension icon
├── popup.js # JS for the popup UI
├── options.html # (Optional) Config page accessible via "Options"
├── options.js
├── icons/ # Extension icon assets
│ └── icon128.png
├── styles/ # CSS for popup/options/content
├── scripts/ # Modular JS (e.g., logger.js, utils.js)
└── assets/ # Static assets (e.g., fonts, templates)