feat: add TradeContext, Subcategory and LastAnalyzedAt

src/Predictalytics.Domain/Entities/TradeContext.cs

@@ -0,0 +1,29 @@
+using Predictalytics.Domain.Enums;
+
+namespace Predictalytics.Domain.Entities;
+
+/// <summary>
+/// High-resolution analytics context for a specific trade.
+/// Collected asynchronously after a trade is discovered to calculate Slippage and Edge.
+/// Only collected for Watchlisted or high-scoring traders to conserve database space.
+/// </summary>
+public class TradeContext
+{
+    public long Id { get; set; }
+
+    /// <summary>The ID of the parent trade.</summary>
+    public long TradeId { get; set; }
+    public Trade Trade { get; set; } = null!;
+
+    /// <summary>The estimated mid-price of the asset roughly 1 minute before the trade execution.</summary>
+    public decimal? PriceBefore1m { get; set; }
+
+    /// <summary>The estimated mid-price of the asset roughly 1 minute after the trade execution.</summary>
+    public decimal? PriceAfter1m { get; set; }
+
+    /// <summary>Calculated slippage: execution price vs PriceBefore1m.</summary>
+    public decimal? EstimatedSlippage { get; set; }
+
+    /// <summary>Estimated order type based on fee or exact price matching.</summary>
+    public OrderType EstimatedOrderType { get; set; } = OrderType.Unknown;
+}