Add implementation for Brioche.download() global function

packages/std/core/global.bri

@@ -82,6 +82,19 @@ declare global {
      * ```
      */
     function glob(...patterns: string[]): Recipe<Directory>;
+
+    /**
+     * Download a file from a URL. Unlike `std.download`, this function does
+     * not take a hash, and it **must** be called with a constant string URL.
+     * The hash of the downloaded file will be saved in the lockfile.
+     *
+     * ## Example
+     *
+     * ```typescript
+     * const file = Brioche.download("http://example.com/");
+     * ```
+     */
+    function download(url: string): Recipe<File>;
   }
 }
 
@@ -155,3 +168,24 @@ declare global {
     },
   });
 };
+(globalThis as any).Brioche.download ??= (url: string): Recipe<File> => {
+  const sourceFrame = source({ depth: 1 }).at(0);
+  if (sourceFrame === undefined) {
+    throw new Error(`Could not find source file to download ${url}`);
+  }
+
+  const sourceFile = sourceFrame.fileName;
+
+  return createRecipe(["file"], {
+    sourceDepth: 1,
+    briocheSerialize: async () => {
+      return await (globalThis as any).Deno.core.ops.op_brioche_get_static(
+        sourceFile,
+        {
+          type: "download",
+          url,
+        },
+      );
+    },
+  });
+};