Consolidate ReconstructedUtxos and Coin Types to Reduce Complexity

Background

Currently, our UTXO reconstruction logic involves an unnecessary three-step type conversion chain:

1. reconstructSingleUtxo returns a ReconstructedUtxos object
2. convertCaravanUtxoToCoin converts it to a Coin object
3. getUtxoFromCoin converts it back to a UTXO object

This creates a confusing data flow and highlights unnecessary complexity in our type system.

Problem

The ReconstructedUtxos and Coin types are conceptually the same thing with minor property naming differences:

ReconstructedUtxos:

{
  txid: string;
  index: number;
  amountSats: string;
  amount: string;
  confirmed: boolean;
  transactionHex: string;
  multisig: any;
  bip32Path: string;
  change: boolean;
}

Coin

{
  prevTxId: string;
  vout: number;
  address: string;
  value: string;
  prevTxHex: string;
  slice?: Slice;
}

Having two types for essentially the same concept leads to:

• Unnecessary conversions between types
• Harder maintenance - changes must be made in multiple places
• Cognitive overhead - developers must understand both types and conversion logic
• Reduced code clarity - the conversion chain makes the logic hard to follow

Proposed Solution

Consolidate these types into a single Coin type (or a unified type) that serves both purposes:

1. Update reconstructSingleUtxo → reconstructSingleCoin

   • Change return type from ReconstructedUtxos to Coin
   • Adjust property names to match Coin interface
   • Derive address from multisig.address

2. Update reconstructUtxosFromPendingTransactions

   • Change return type to use Coin[] instead of ReconstructedUtxos[]
   • Update all internal references

3. Eliminate convertCaravanUtxoToCoin

   • This function becomes unnecessary after consolidation

4. Update hook names and signatures:

   • Consider renaming useReconstructedUtxos to reflect coin terminology if appropriate
   • Update matchPsbtInputsToUtxos parameter types

5. Update buildUtxoFromSpendingTransaction

   • Simplify by removing the conversion step
   • Directly use reconstructed coin with getUtxoFromCoin