A basic pdf viewer for merging and annotating pdf documents, tested to work in Chrome and Firefox, there are some issues in Safari (doesn't register pointer events on elements that overflow svg).
Annotations are baked into the pdf content stream as regular drawing instructions and may not be hid or removed ocne added as is the case with regular pdf annotations.
Also, it is possible to delete / insert blank pages.
git clone https://github.com/alics1996/pdf-viewer-svelte.git
cd pdf-viewer-svelte
npm i
npm run dev