Fetch File To Site

Downloads a file from a public URL DIRECTLY onto the hosting site, and RESIZES or CONVERTS images on the way in (resize, webp, avif, jpg, quality) — this is the only image processing available for a hosting server, because the container itself has no cwebp, no ImageMagick and no sharp. The CORE fetches the bytes (full internet + memory) and writes them to `path` under /data/site. It downloads the user's OWN images/logos/PDFs (any domain) or stock photos straight to the server, without base64-encoding or chunking large files through the chat. It also bypasses the sandbox's limited outbound DNS (shell `curl` in site_run_command reaches only whitelisted hosts like images.unsplash.com; site_fetch reaches ANY host). path is the destination inside the site (assets/img/hero.webp). Binary-safe, up to 20MB per file.

IMAGE PROCESSING happens before the file lands: resize accepts '1200x' (width, height follows the aspect ratio), 'x800' (height), '1200x800' (fit inside that box, never cropped or stretched) or '50%'; image_format converts to 'webp', 'jpg', 'png' or 'avif'; quality is 1-100 for the lossy formats (default 82). The hosting container has no cwebp, no ImageMagick and no sharp, so this is how a photo becomes a right-sized WebP — download a 4000px original and write a 1200px WebP in one call. Images are never enlarged past their real size; upscaling only adds bytes. Not for SVG: an SVG is written through untouched (it is already scalable), and it cannot be rasterised into a PNG favicon here — for that install sharp with site_run_command(background=true).