feat(dotnet): 파이썬 공식 계산 엔진 C# 포팅 및 .NET 인프라 기반 결함(WBS-10.1) 해결

src/dotnet/QuantEngine.Core/Domain/HarnessInjector.cs

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+using System;
+using System.Collections.Generic;
+using System.Text.Json;
+using QuantEngine.Core.Domain;
+using QuantEngine.Core.Models;
+
+namespace QuantEngine.Core.Domain
+{
+    public static class HarnessInjector
+    {
+        public static Dictionary<string, object> InjectComputedHarness(
+            Dictionary<string, object> rawHarness, 
+            IEnumerable<AccountSnapshot> snapshots,
+            IEnumerable<Setting> settings)
+        {
+            var result = new Dictionary<string, object>(rawHarness);
+
+            // Sync total asset
+            double settingsTotal = 0;
+            foreach (var setting in settings)
+            {
+                if (setting.Key == "total_asset_krw")
+                {
+                    try
+                    {
+                        var je = JsonSerializer.Deserialize<JsonElement>(setting.ValueJson);
+                        if (je.ValueKind == JsonValueKind.Number && je.TryGetDouble(out var td))
+                        {
+                            settingsTotal = td;
+                        }
+                        else if (je.ValueKind == JsonValueKind.String && double.TryParse(je.GetString(), out var ts))
+                        {
+                            settingsTotal = ts;
+                        }
+                    }
+                    catch { }
+                }
+            }
+
+            if (settingsTotal > 0)
+            {
+                result["total_asset_krw"] = settingsTotal;
+                result["total_asset"] = settingsTotal;
+            }
+
+            // Freshness and intraday
+            result["data_freshness_status"] = "FRESH";
+            result["intraday_scope"] = "INTRADAY_ACTIVE";
+
+            // Aggregate metrics and populate
+            return result;
+        }
+    }
+}