Implement the script that handles preparing the manifest for release

scripts/prepareManifest.mjs

@@ -4,11 +4,31 @@ manifest file that we need to do in order to release the system. This
 can include removing dev-only fields/attributes that end users will
 never, and should never, care about nor need.
 */
+import { readFile, writeFile } from "fs/promises";
 
-// TODO: load the manifest
+const MANIFEST_PATH = `system.json`;
 
-// TODO: remove all files that start with dev/ from the esmodules list
+let manifest;
+try {
+	manifest = JSON.parse(await readFile(MANIFEST_PATH, `utf-8`));
+} catch {
+	console.error(`Failed to parse manifest file.`);
+	process.exit(1);
+};
 
-// TODO: remove flags.hotReload
 
-// TODO: write the new manifest to disk
+// Filter out dev-only resources
+if (manifest.esmodules) {
+	manifest.esmodules = manifest.esmodules.filter(
+		filepath => !filepath.startsWith(`dev/`)
+	);
+};
+
+// Remove dev flags
+delete manifest.flags?.hotReload;
+
+if (Object.keys(manifest.flags).length === 0) {
+	delete manifest.flags;
+};
+
+await writeFile(MANIFEST_PATH, JSON.stringify(manifest, undefined, `\t`));