Replace direct node js types imports

[reaktivo]

Problem

When attempting to integrate this library into a project I noticed I started receiving compilation errors due to dependencies in Node specific types, although my project is web only.

src/types/index.ts, src/core/QRCodeStyling.ts, and src/core/QRSVG.ts all contain top-level imports from jsdom and canvas, this prevents the library from being compiled correctly on projects with skipLibCheck set to true.

import { DOMWindow, JSDOM } from "jsdom";   // types/index.ts
import nodeCanvas from "canvas";            // types/index.ts
import { Canvas as NodeCanvas, Image } from "canvas"; // QRCodeStyling.ts
import { Image } from "canvas";             // QRSVG.ts

These are Node.js-only packages. Their presence as unconditional top-level imports causes two problems for browser consumers:

1. Bundlers fail or warn — webpack/vite/rollup try to resolve jsdom and canvas and either error out or produce warnings about missing Node built-ins.
2. Generated .d.ts files reference the packages — anyone using the published type declarations needs @types/jsdom and canvas installed, even for a browser-only project.

Solution

Replace the three package imports with minimal structural (duck-type) interfaces defined inside the library itself:

Old	New
DOMWindow from jsdom	BrowserWindow (document + XMLSerializer + Image + XMLHttpRequest + FileReader)
typeof JSDOM from jsdom	JSDOMConstructor
typeof nodeCanvas from canvas	NodeCanvasFactory
Canvas from canvas	NodeCanvasElement
Image from canvas	NodeCanvasImage

The interfaces capture only the surface the library actually uses, so:

• Existing Node.js usage (new QRCodeStyling({ nodeCanvas, jsdom })) continues to work — the real canvas and jsdom objects satisfy the interfaces structurally.
• Browser bundles no longer see any reference to jsdom or canvas.
• Published .d.ts files no longer expose the external packages.

Verification

npx tsc --noEmit   # 0 new errors (pre-existing @types/ws issue unchanged)