Enhance error handling in coordination procedures

- Updated the coordinationExecutor to return a partial result containing leader and faults information when a follower's routine fails, allowing for better metric recording.

Author: lionakhnazarov

pkg/tbtc/coordination.go

@@ -454,7 +454,15 @@ func (ce *coordinationExecutor) coordinate(
 			if ce.metricsRecorder != nil {
 				ce.metricsRecorder.IncrementCounter(clientinfo.MetricCoordinationLeaderTimeoutTotal, 1)
 			}
-			return nil, fmt.Errorf(
+			// Return a partial result with leader and faults information
+			partialResult := &coordinationResult{
+				wallet:   ce.coordinatedWallet,
+				window:   window,
+				leader:   leader,
+				proposal: nil, // no proposal on failure
+				faults:   faults,
+			}
+			return partialResult, fmt.Errorf(
 				"failed to execute follower's routine: [%v]",
 				err,
 			)

pkg/tbtc/node.go

@@ -1150,14 +1150,22 @@ func executeCoordinationProcedure(
 		// Record window metrics for failed coordination
 		if node.windowMetricsTracker != nil {
 			walletPublicKeyHash := bitcoin.PublicKeyHash(walletPublicKey)
+			// Extract leader and faults from partial result if available
+			// (e.g., when follower routine fails, we know who the leader was)
+			leader := chain.Address("")
+			var faults []*coordinationFault
+			if result != nil {
+				leader = result.leader
+				faults = result.faults
+			}
 			node.windowMetricsTracker.recordWalletCoordination(
 				window,
 				walletPublicKeyHash,
-				chain.Address(""), // unknown leader on failure
+				leader,
 				"",
 				false,
 				duration,
-				nil,
+				faults,
 				err, // capture the error message
 			)
 		}