Chrome Extension Monetization & Shadow-DOM Boilerplate Kit (Manifest V3 + License Key Paywall Worker for Payhip/Ko-fi/Gumroad/Stripe)

Ship and monetize your own Manifest V3 Chrome Extension in an afternoon without paying $99–$149 for bloated SaaS boilerplates. Includes: (1) Production MV3 Extension Starter with isolated Shadow-DOM content script injection (100% immune to host-page CSS resets), Chrome SidePanel + Popup dual-mount UI, and background service worker heartbeat alarms, plus (2) Zero-dependency Cloudflare Worker + KV License Key Server (worker.js) that automatically generates and verifies license keys from Payhip, Ko-fi Shop, Gumroad, and Stripe webhooks with a 3-device fingerprint seat limit.