Summary

Fixes two issues related to Bitcoin transaction fee calculation:

1. Fix inaccurate vsize estimation in build-tx when using --max-inputs
2. Add fee, fee rate, and vsize display to verify-psbt command

Problem

When using --max-inputs parameter in rooch bitcoin build-tx, the fee calculation used a simplified hardcoded formula:

let estimated_vsize = 100 + utxo_count * 60 + 2 * 43;

This resulted in severely underestimated vsize (e.g., 7,026 bytes vs actual 18,990 bytes for 114 inputs), causing transactions to have only 19 satoshis fee instead of the expected ~19,000 satoshis for a 1 sat/vbyte rate.

Changes

build_tx.rs

• Replace hardcoded formula with accurate TransactionBuilder::estimate_vbytes_with() method
• Pre-resolve change address outside async map closure
• Remove unnecessary 1000 satoshi deduction from fee calculation

transaction_builder.rs

• Make estimate_vbytes_with() public to allow reuse in build_tx.rs

verify_psbt.rs

• Add total_input_sat and total_output_sat fields to track transaction amounts
• Calculate and display fee information (fee, fee rate, vsize)
• Add appropriate handling for cases where witness_utxo is missing

Testing

Verified the fix by:

1. Building transactions with the new code shows correct vsize estimation
2. verify-psbt now displays fee information:

   Fee: XXXXX satoshi (0.XXXXXXXX BTC)
   Fee rate: X.XX sat/vbyte
   Transaction vsize: XXXXX bytes
   

Fixes #XXX