Mining: blocks now include mempool txs, select spendable txs by fee, and pay coinbase as base reward + fees in main.c.
- Consensus: block validation now enforces coinbase accounting and rejects invalid coinbase placement, including coinbase on amount2, in block.c and transaction.c.
- Chain state: rollback now rebuilds currentSupply/currentReward, and block addition preflights spendability before mutating balances in chain.c.
- Orphans/reorgs: orphan retry is safer, rollback-triggered sync reattaches orphans immediately, and transient orphan failures no longer drop blocks in orphan_pool.c and main.c.
- Networking/mempool: node lifecycle now initializes the mempool, broadcasts can exclude one peer, and mempool snapshotting supports mining selection in net_node.c and txmempool.c.
- Ledger simulation: added non-mutating spendable-transaction selection for block assembly in balance_sheet.c.
