How I Built a 100% Client-Side PDF Toolkit with Zero Cloud Uploads

Here is a bizarre architectural paradox of the modern web: In 2026, our browser tabs can execute C++ via WebAssembly at near-native speed, run local LLMs with WebGPU, and render complex 3D worlds. Yet, whenever an engineer needs to merge two PDF pages, add a protective watermark, or compress a document under 2MB, the entire industry still defaults...