ML data included by default, --exif is the opt-in, --all aliases --exif

ML data (face detections, CLIP embeddings) is now fetched by default
in backup-metadata. Use --no-ml to skip it. EXIF extraction (which
requires downloading every file) remains opt-in via --exif. --all is
an alias for --exif.

src/metadata-backup.ts

@@ -120,7 +120,7 @@ export const runMetadataBackup = async (
     opts?: MetadataBackupOptions,
 ): Promise<void> => {
     const log = opts?.onProgress ?? (() => {});
-    const wantML = opts?.mlData ?? false;
+    const wantML = opts?.mlData ?? true;
     const wantExif = opts?.exif ?? false;
 
     mkdirSync(outDir, { recursive: true });