fix: the --all-as-mirrors flag itself was never added

The function landed but the argparse anchor did not match the real formatting,
so the command existed and could not be invoked. Caught by running it rather
than assuming the patch applied.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

scripts/import_from_github.py

@@ -207,6 +207,10 @@ def main() -> int:
         "--mirror", action="store_true",
         help="import read-only pull mirrors instead of writable repos. NOTE: mirrors CANNOT run CI.",
     )
+    ap.add_argument(
+        "--all-as-mirrors", action="store_true",
+        help="bulk DR copy: every active repo on the account, read-only, no CI, zero deploy risk",
+    )
     args = ap.parse_args()
 
     if args.list_candidates: