refactor changes

src/api/pdf.ts

@@ -1,13 +1,26 @@
 // PDF export. The source is built here and compiled there; these two calls are the boundary.
 
 import { call, type ImageInput } from "../ipc";
+import { fontsUsed, type DocumentFonts } from "../model/fonts";
 
 /**
  * Compiles Typst source to PDF bytes. Warnings do not come back through the return value, because
  * the answer is raw bytes and has no room for a second one: they arrive on `pdf-warnings` instead.
+ *
+ * `fonts` is the document's own pair, and what crosses the boundary is which faces to load rather
+ * than their bytes: a bundled id the backend already has compiled in, a system family name it can
+ * look up. The source names the families itself, so this only has to make sure the compiler can
+ * see them.
  */
-export const pdfCompile = (source: string, images: readonly ImageInput[]) =>
-  call<ArrayBuffer>("pdf_compile", { source, images });
+export const pdfCompile = (source: string, images: readonly ImageInput[], fonts: DocumentFonts) => {
+  const used = fontsUsed(fonts);
+  return call<ArrayBuffer>("pdf_compile", {
+    source,
+    images,
+    bundledFonts: used.bundled,
+    systemFonts: used.system,
+  });
+};
 
 /**
  * Writes the finished file wherever the native save panel pointed.