🤖 Claude Code Review

Status: Complete

This PR adds a nil check for block.CoinbaseTx before calling utxoDiff.ProcessTx() to prevent a panic when blocks loaded from seed files have no coinbase transaction.

Analysis:

The fix correctly addresses a legitimate edge case. In model/Block.go lines 288-291, NewBlockFromBytes sets CoinbaseTx to nil when the coinbase transaction is all zeros (empty), which occurs when blocks are loaded from seed files rather than being assembled normally.

The change is minimal and defensive - it adds a simple nil check alongside the existing utxoDiff != nil check before processing the coinbase transaction. This prevents a panic without affecting normal block processing.

No issues found.