refactor(dotnet): normalize collection read model inputs

src/dotnet/QuantEngine.Application/Services/CollectionReadModelService.cs

@@ -13,9 +13,31 @@ public sealed class CollectionReadModelService : ICollectionReadModelService
     }
 
     public Task<CollectionDashboardStateRecord> GetDashboardStateAsync() => _repository.GetDashboardStateAsync();
-    public Task<List<CollectionRunRecord>> GetRecentRunsAsync(int limit = 20) => _repository.GetRecentRunsAsync(limit);
-    public Task<List<CollectionSnapshotRecord>> GetRunSnapshotsAsync(string runId) => _repository.GetRunSnapshotsAsync(runId);
-    public Task<List<CollectionErrorRecord>> GetRunErrorsAsync(string runId, int limit = 50) => _repository.GetRunErrorsAsync(runId, limit);
-    public Task<List<CollectionSnapshotRecord>> GetLatestSnapshotsForTickerAsync(string ticker, int limit = 10) => _repository.GetLatestSnapshotsForTickerAsync(ticker, limit);
+
+    public Task<List<CollectionRunRecord>> GetRecentRunsAsync(int limit = 20)
+        => _repository.GetRecentRunsAsync(NormalizeLimit(limit, 1, 200));
+
+    public Task<List<CollectionSnapshotRecord>> GetRunSnapshotsAsync(string runId)
+        => _repository.GetRunSnapshotsAsync(RequireValue(runId, nameof(runId)));
+
+    public Task<List<CollectionErrorRecord>> GetRunErrorsAsync(string runId, int limit = 50)
+        => _repository.GetRunErrorsAsync(RequireValue(runId, nameof(runId)), NormalizeLimit(limit, 1, 200));
+
+    public Task<List<CollectionSnapshotRecord>> GetLatestSnapshotsForTickerAsync(string ticker, int limit = 10)
+        => _repository.GetLatestSnapshotsForTickerAsync(RequireValue(ticker, nameof(ticker)), NormalizeLimit(limit, 1, 100));
+
     public Task<List<PriceHistorySummaryRecord>> GetPriceHistorySummaryAsync() => _repository.GetPriceHistorySummaryAsync();
+
+    private static string RequireValue(string value, string parameterName)
+    {
+        if (string.IsNullOrWhiteSpace(value))
+        {
+            throw new ArgumentException("Value is required.", parameterName);
+        }
+
+        return value.Trim();
+    }
+
+    private static int NormalizeLimit(int limit, int min, int max)
+        => Math.Clamp(limit, min, max);
 }