TON: catch-up stalled when oos does not drop

TON: catch-up stalled when oos does not drop

• seqno>0 + ~27h behind + 0.1% is not 'won't start' — validator is up.
• If local seqno rises but out_of_sync_sec grows: catch-up slower than tip (serializer / I/O). UI says that, not 0.1% lag closed.