add new bitcoin electrum SPV provider

go.mod

@@ -2,4 +2,20 @@ module code.stevenpolley.net/steven/ynab-portfolio-monitor
 
 go 1.22
 
-// Goal is no third party dependencies
+// Goal is no third party dependencies 
+// Edit 2025-09-30 - brought in btcd dependency because crypto is hard
+
+require (
+	github.com/btcsuite/btcd v0.24.2
+	github.com/btcsuite/btcd/btcutil v1.1.6
+)
+
+require (
+	github.com/btcsuite/btcd/btcec/v2 v2.1.3 // indirect
+	github.com/btcsuite/btcd/chaincfg/chainhash v1.1.0 // indirect
+	github.com/btcsuite/btclog v0.0.0-20170628155309-84c8d2346e9f // indirect
+	github.com/decred/dcrd/crypto/blake256 v1.0.0 // indirect
+	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1 // indirect
+	golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9 // indirect
+	golang.org/x/sys v0.0.0-20200814200057-3d37ad5750ed // indirect
+)