compat: check the middlewared METHODS we call, not just the symbols we wrap

This gap was hiding a catastrophe. TrueNAS 26 deletes plugins/zfs_/dataset.py and
plugins/zfs_/snapshot.py outright, taking zfs.dataset.query, zfs.snapshot.query and
zfs.snapshot.delete with them (26 uses filesystem.statfs and zfs.resource.*).

Nothing about the five cloud_backup files reveals that, so every other check went
green -- including the one I had just added. The patch would have applied cleanly
and then failed on the first backup, or worse: snapshotted fine and failed to
DELETE, orphaning one snapshot per descendant dataset (250 on a real pool) on every
run, forever.

So 26 is BROKEN and the nested module will not apply there. The async/sync wrapper
work and the vendored get_dataset_recursive stay -- they are correct and necessary
-- but 26 is not supported until the ZFS calls are ported, and that needs a real 26
box to verify. Shipping a port nobody has run is the failure this project exists to
avoid.

Also: do_delete is recognised as delete (24.10/25.04 use the CRUDService
convention), which was reporting both as BROKEN -- a false verdict that would have
disabled nested snapshots on boxes where they work.

patch/apply.sh

@@ -640,10 +640,16 @@ if _tc_nested is not None:
             return await _tc_orig_restic_backup(middleware, job, cloud_backup, *args, **kwargs)
         finally:
             try:
+                # logger= must be passed here too, exactly as the sync variant does.
+                # run_in_thread forwards **kwargs (functools.partial), and without it
+                # cleanup_task gets logger=None -- so every teardown warning ("could
+                # not unmount X") is silently swallowed on <= 25.10, which is most
+                # boxes. The two wrappers must differ ONLY in how they reach the core.
                 await middleware.run_in_thread(
                     _tc_nested.cleanup_task,
                     middleware,
                     f"cloud_backup-{cloud_backup.get('id', 'onetime')}",
+                    logger=getattr(middleware, "logger", None),
                 )
             except Exception as e:
                 middleware.logger.warning("truecloud-patch: staging cleanup failed: %r", e)