add update functionality

scripts/releaseArtifacts.mjs

@@ -38,6 +38,10 @@ export async function readReleaseArtifacts(directory) {
 
 /** Mark a successful signed build with hashes of its exact publishable files. */
 export async function writeReleaseManifest(directory, feedUrl) {
+  // JSON is valid YAML. This gives the standalone PHP host a strict, dependency-free parser.
+  const metadataPath = join(directory, 'latest.yml')
+  const metadata = parse(await readFile(metadataPath, 'utf8'))
+  await writeFile(metadataPath, `${JSON.stringify(metadata, null, 2)}\n`)
   const release = await readReleaseArtifacts(directory)
   const manifest = {
     version: release.version,