Add rate field to GetQuoteResponse

csharp/src/Infrastructure/Quote/QuoteService.cs

@@ -214,6 +214,7 @@ await CalculateTotalFeeAsync(route, amount, rewardAmountInDestNative: rewardAmou
             TotalServiceFee = totalServiceFee,
             TotalExpenseFee = totalExpenseFee,
             TotalRewardFee = totalRewardFee,
+            Rate = swapRate.Truncate(6),
             SourceSolverAddress = route.SourceWallet.Address,
             DestinationSolverAddress = route.DestinationWallet.Address,
             Route = route,

csharp/src/Shared.Models/Models/QuoteDto.cs

@@ -4,13 +4,15 @@ namespace Train.Solver.Shared.Models;
 
 public class QuoteDto
 {
-    public BigInteger TotalFee { get; set; } 
+    public BigInteger TotalFee { get; set; }
 
-    public BigInteger TotalServiceFee { get; set; } 
+    public BigInteger TotalServiceFee { get; set; }
 
     public BigInteger TotalExpenseFee { get; set; }
 
     public BigInteger TotalRewardFee { get; set; }
 
     public BigInteger ReceiveAmount { get; set; }
+
+    public decimal Rate { get; set; }
 }

csharp/src/Shared.Proto/SolverProtoMapper.cs

@@ -53,6 +53,7 @@ public static class SolverProtoMapper
         TotalExpenseFee = quote.TotalExpenseFee.ToString(),
         TotalRewardFee = quote.TotalRewardFee.ToString(),
         Amount = quote.Amount.ToString(),
+        Rate = quote.Rate.ToString(System.Globalization.CultureInfo.InvariantCulture),
     };
 
     #endregion

protos/solver.proto

@@ -69,6 +69,7 @@ message GetQuoteResponse {
   string total_expense_fee = 11;     // BigInteger as string (source token units)
   string total_reward_fee = 12;      // BigInteger as string (source token units)
   string amount = 13;                // BigInteger as string (source amount — useful for reverse quotes)
+  string rate = 14;                  // decimal as invariant string — dest/source conversion rate, truncated to 6 decimals
 }
 
 message RewardInfo {