Takumi: route images, shared options, fonts and WebAssembly

takumiOptions in the getConfig() of a route gives it an Open Graph image: title and description for the default template, or a node to draw it yourself. A static page gets the image prerendered next to it (/about.webp), a dynamic page renders it on request under /_takumi, and both receive the og:image meta tags like a content page. A function form receives the route params.
options on takumiPlugin() applies to every image, put values resolved once there, like the fonts from googleFonts(). The options of generate() override them per page.
googleFonts and fontFromUrl are re-exported from fumapress/plugins/takumi, and fumapress/plugins/takumi.wasm exports Takumi's WebAssembly build for options.module: takumi-js no longer needs to be installed next to fumapress, which used to end up with two copies.
The options accepted by generate() no longer drop quality, lossless and module.