try reversing slash direction for typst on windows

Author: gordonwoodhull

src/core/brand/brand.ts

@@ -232,16 +232,21 @@ export class Brand {
     return fonts ?? [];
   }
 
+  // does typst want forward-slash paths?
+  relativePath(path: string): string {
+    const pathPrefix = relative(this.projectDir, this.brandDir);
+    return join(pathPrefix, path).replace("\\", "/");
+  }
+
   getLogoResource(name: string): BrandLogoExplicitResource {
     const entry = this.data.logo?.images?.[name];
     if (!entry) {
       return { path: name };
     }
-    const pathPrefix = relative(this.projectDir, this.brandDir);
     if (typeof entry === "string") {
-      return { path: join(pathPrefix, entry) };
+      return { path: this.relativePath(entry) };
     }
-    entry.path = join(pathPrefix, entry.path);
+    entry.path = this.relativePath(entry.path);
     return entry;
   }