Fix B6: Market concurrency lock, watchlist exclusion from cleanup, optimized trade ID deduplication query, and TradeHistoryWorker sync logic

src/Predictalytics.Infrastructure/Data/Repositories/MarketRepository.cs

@@ -28,21 +28,29 @@ public class MarketRepository : IMarketRepository
 
     public async Task AddOrUpdateAsync(Market market, CancellationToken ct = default)
     {
-        TruncateMarketStrings(market);
-
-        var existing = await _db.Markets.Include(m => m.Outcomes)
-            .FirstOrDefaultAsync(m => m.Platform == market.Platform && m.PlatformMarketId == market.PlatformMarketId, ct);
-
-        if (existing != null)
+        await _syncSemaphore.WaitAsync(ct);
+        try
         {
-            UpdateMarketFields(existing, market);
-        }
-        else
-        {
-            _db.Markets.Add(market);
-        }
+            TruncateMarketStrings(market);
 
-        await _db.SaveChangesAsync(ct);
+            var existing = await _db.Markets.Include(m => m.Outcomes)
+                .FirstOrDefaultAsync(m => m.Platform == market.Platform && m.PlatformMarketId == market.PlatformMarketId, ct);
+
+            if (existing != null)
+            {
+                UpdateMarketFields(existing, market);
+            }
+            else
+            {
+                _db.Markets.Add(market);
+            }
+
+            await _db.SaveChangesAsync(ct);
+        }
+        finally
+        {
+            _syncSemaphore.Release();
+        }
     }
 
     public async Task AddOrUpdateRangeAsync(IEnumerable<Market> markets, CancellationToken ct = default)

src/Predictalytics.Infrastructure/Data/Repositories/TradeRepository.cs

@@ -89,10 +89,13 @@ public class TradeRepository : ITradeRepository
             .ToListAsync(ct);
     }
     
-    public async Task<HashSet<string>> GetKnownPlatformTradeIdsAsync(PlatformType platform, int traderId, CancellationToken ct = default)
+    public async Task<HashSet<string>> GetKnownPlatformTradeIdsAsync(PlatformType platform, int traderId, IEnumerable<string> platformTradeIds, CancellationToken ct = default)
     {
+        var idList = platformTradeIds.ToList();
+        if (idList.Count == 0) return new HashSet<string>();
+
         var ids = await _db.Trades
-            .Where(t => t.Platform == platform && t.TraderId == traderId)
+            .Where(t => t.Platform == platform && t.TraderId == traderId && idList.Contains(t.PlatformTradeId))
             .Select(t => t.PlatformTradeId)
             .ToListAsync(ct);
         return new HashSet<string>(ids);

src/Predictalytics.Infrastructure/Data/Repositories/TraderRepository.cs

@@ -92,6 +92,7 @@ public class TraderRepository : ITraderRepository
     public async Task<IReadOnlyList<Trader>> GetTradersForCleanupAsync(DateTime inactiveSince, DateTime errorSince, int take = 50, CancellationToken ct = default)
     {
         return await _db.Traders
+            .Where(t => t.IsAutoDiscovered && !t.WatchlistEntries.Any())
             .Where(t => (t.LastPolledAt != null && t.LastPolledAt < inactiveSince) ||
                         (t.LastApiErrorAt != null && t.LastApiErrorAt < errorSince))
             .OrderBy(t => t.LastApiErrorAt ?? DateTime.MaxValue) // Prioritize errors first