WalletSynchronizer now pipelines JSON-RPC requests (address subscribes,
histories, tx downloads and Merkle proofs run in parallel batches) and
keeps per-connection caches of downloaded transactions and verified
proofs, so notification-triggered resyncs only cost the delta.
The app connects automatically when a wallet opens, keeps one
synchronizer per connection, and queues notifications that arrive
during a sync instead of dropping them: incoming transactions now show
up within seconds.
TransactionFactory now selects only confirmed UTXOs (height > 0), so
mempool funds are visible as pending balance but never spendable, with
a clear error when only unconfirmed funds are available. GUI and CLI
labels updated to "in attesa di conferma (non spendibile)".
davide