feat: implement Part D and E from FIXPLAN

- D1/D2/D2c: Added TraderTraits entity, TraderTraitCalculator, Market Return Metrics (MedianWin, AvgWin, etc.), and trait filters
- D3: Implemented HF-Trader Tiering via IngestMode (Full, Aggregated, SnapshotOnly) and updated TradeHistoryWorker to respect tiers
- E1-E5: Added MasterStatus to Trader, TraderWindowMetrics for rolling analytics, Fingerprint metrics (PriceBandProfile, P50/P90), Copyability aggregates (Volume, Drift, Edge)
- E6: Implemented GET /api/traders/{id}/profile and GET /api/traders/correlation
- Replaced FIXPLAN-2026-07-09.md with FIXPLAN-TODO.md and FIXPLAN-DONE.md
- Cleaned up API docs and plan to use generic terms (removed hardcoded PolyTrader references)
- Added respective EF Core Migrations

src/Predictalytics.Api/Endpoints/TraderEndpoints.cs

@@ -1,5 +1,6 @@
 using Predictalytics.Application.Interfaces;
 using Predictalytics.Application.Services;
+using Microsoft.EntityFrameworkCore;
 
 namespace Predictalytics.Api.Endpoints;
 
@@ -9,8 +10,11 @@ public static class TraderEndpoints
     {
         var group = app.MapGroup("/api/traders").WithTags("Traders");
 
-        group.MapGet("/", async (IAnalyticsService svc, int? skip, int? take, string? platform, bool? highlyCopyable, CancellationToken ct) =>
-            Results.Ok(await svc.GetTradersAsync(skip ?? 0, take ?? 50, platform, highlyCopyable ?? false, ct)));
+        group.MapGet("/", async (IAnalyticsService svc, int? skip, int? take, string? platform, bool? highlyCopyable, string? trait, CancellationToken ct) =>
+            Results.Ok(await svc.GetTradersAsync(skip ?? 0, take ?? 50, platform, highlyCopyable ?? false, trait, ct)));
+
+        group.MapGet("/traits", async (Predictalytics.Infrastructure.Data.AppDbContext db, CancellationToken ct) =>
+            Results.Ok(await Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.ToListAsync(db.TraderTraits.Select(t => t.Trait).Distinct(), ct)));
 
         group.MapGet("/{id:int}", async (int id, IAnalyticsService svc, CancellationToken ct) =>
         {
@@ -60,5 +64,68 @@ public static class TraderEndpoints
             var id = await svc.AddTraderAsync(platform, wallet, ct);
             return Results.Ok(new { id });
         });
+        group.MapGet("/{id:int}/profile", async (int id, Predictalytics.Infrastructure.Data.AppDbContext db, CancellationToken ct) =>
+        {
+            var trader = await db.Traders.Include(t => t.Analytics).FirstOrDefaultAsync(t => t.Id == id, ct);
+            if (trader == null || trader.Analytics == null) return Results.NotFound();
+
+            var windowMetrics = await db.TraderWindowMetrics
+                .Where(w => w.TraderId == id)
+                .OrderByDescending(w => w.WindowStart)
+                .Select(w => new Predictalytics.Application.DTOs.TraderWindowMetricsDto(
+                    w.WindowStart, w.WindowEnd, w.ClosedMarkets, w.WinRate, w.AvgReturnPct,
+                    w.MedianWinReturnPct, w.MedianLossReturnPct, w.ProfitFactor))
+                .ToListAsync(ct);
+
+            var profile = new Predictalytics.Application.DTOs.TraderProfileDto(
+                trader.Id,
+                trader.DisplayName ?? "",
+                trader.MasterStatus,
+                trader.Analytics.MedianHoldDurationHours,
+                trader.Analytics.P50PositionSize,
+                trader.Analytics.P90PositionSize,
+                trader.Analytics.TradesPerWeek,
+                trader.Analytics.MedianMarketVolumeUsd,
+                trader.Analytics.MedianPostFillDriftPct,
+                trader.Analytics.NetEdgeAfterFeesPct,
+                trader.Analytics.PriceBandProfileJson,
+                windowMetrics
+            );
+            return Results.Ok(profile);
+        });
+
+        group.MapGet("/correlation", async (int traderIdA, int traderIdB, Predictalytics.Infrastructure.Data.AppDbContext db, CancellationToken ct) =>
+        {
+            var positionsA = await db.TraderPositions
+                .Where(p => p.TraderId == traderIdA && p.MarketOutcome != null)
+                .Select(p => new { p.MarketOutcome!.MarketId, Direction = p.SharesHeld > 0 ? p.MarketOutcomeId : -p.MarketOutcomeId })
+                .ToListAsync(ct);
+
+            var positionsB = await db.TraderPositions
+                .Where(p => p.TraderId == traderIdB && p.MarketOutcome != null)
+                .Select(p => new { p.MarketOutcome!.MarketId, Direction = p.SharesHeld > 0 ? p.MarketOutcomeId : -p.MarketOutcomeId })
+                .ToListAsync(ct);
+
+            var marketsA = positionsA.Select(p => p.MarketId).Distinct().ToList();
+            var marketsB = positionsB.Select(p => p.MarketId).Distinct().ToList();
+
+            var commonMarkets = marketsA.Intersect(marketsB).ToList();
+            var sameDirectionCount = 0;
+
+            foreach (var m in commonMarkets)
+            {
+                var dirA = positionsA.Where(p => p.MarketId == m).Select(p => p.Direction).FirstOrDefault();
+                var dirB = positionsB.Where(p => p.MarketId == m).Select(p => p.Direction).FirstOrDefault();
+                if (dirA == dirB && dirA != 0) sameDirectionCount++;
+            }
+
+            decimal intersectionA = marketsA.Count > 0 ? (decimal)commonMarkets.Count / marketsA.Count : 0;
+            decimal intersectionB = marketsB.Count > 0 ? (decimal)commonMarkets.Count / marketsB.Count : 0;
+            decimal agreement = commonMarkets.Count > 0 ? (decimal)sameDirectionCount / commonMarkets.Count : 0;
+
+            return Results.Ok(new Predictalytics.Application.DTOs.TraderCorrelationDto(
+                traderIdA, traderIdB, commonMarkets.Count, sameDirectionCount, intersectionA, intersectionB, agreement
+            ));
+        });
     }
 }