feat(api): build Parts from DB PlateDetails (QtyNstd) instead of file inference

- Add GetPartsFromDbAsync(NestHeader) to aggregate quantities and plate indices
- Use NestName + CopyID filter to select correct program set
- Preserve original drawing name case; normalize grouping to avoid duplicates
- Replace PepHelper.GetParts(nest) usage with DB-driven result

PepApi.Core/Controllers/NestsController.cs

@@ -214,7 +214,7 @@ public class NestsController : ControllerBase
             DateLastModified = info.ModifiedDate!.Value,
             Material = PepHelper.GetMaterial(nest),
             Plates = PepHelper.GetPlates(nest),
-            Parts = PepHelper.GetParts(nest),
+            Parts = await GetPartsFromDbAsync(info),
             NumberOfTestSquares = PepHelper.GetTestSquareCount(nest),
             AreTestSquaresOutOfSequence = !PepHelper.AreTestSquaresInCorrectOrder(nest),
             Customer = info.CustomerName,
@@ -228,4 +228,52 @@ public class NestsController : ControllerBase
 
         return details;
     }
+
+    // Build Parts using database PlateDetail.QtyNstd instead of calculating from files
+    private async Task<List<PepApi.Core.Models.Part>> GetPartsFromDbAsync(NestHeader info)
+    {
+        // Filter by NestName and CopyID to get the correct set for this program
+        var nestName = info.NestName;
+        var copyId = info.CopyID;
+
+        // Avoid method calls on columns in the WHERE clause to keep index usage optimal
+        var plateDetails = await _db.PlateDetails
+            .Where(p => p.NestName == nestName && p.CopyID == copyId)
+            .Select(p => new { p.Drawing, p.QtyNstd, p.QtyReq, p.PlateNumber })
+            .ToListAsync();
+
+        // Group by drawing name, aggregate nested and required quantities
+        var groups = plateDetails
+            .Where(p => !string.IsNullOrWhiteSpace(p.Drawing))
+            .GroupBy(p => p.Drawing.Trim().ToUpper());
+
+        var parts = new List<PepApi.Core.Models.Part>();
+
+        foreach (var g in groups)
+        {
+            var qtyNested = g.Sum(x => x.QtyNstd ?? 0);
+            var qtyReq = g.Select(x => x.QtyReq ?? 0).DefaultIfEmpty(0).Max();
+
+            // Use PlateNumber from DB; convert to 0-based index to align with previous behavior
+            var nestedOn = g
+                .Where(x => (x.QtyNstd ?? 0) > 0 && x.PlateNumber.HasValue)
+                .Select(x => x.PlateNumber!.Value - 1)
+                .Distinct()
+                .OrderBy(i => i)
+                .ToArray();
+
+            // Preserve the original case for Name if available
+            var originalName = g.Select(x => x.Drawing).FirstOrDefault(x => !string.IsNullOrWhiteSpace(x)) ?? g.Key;
+
+            parts.Add(new PepApi.Core.Models.Part
+            {
+                Name = originalName,
+                QtyNested = qtyNested,
+                QtyRequired = qtyReq,
+                NestedOn = nestedOn
+            });
+        }
+
+        return parts.OrderBy(p => p.Name).ToList();
+    }
 }