fix: revert FillExtents/FillLinear FillHelpers.Tile calls (not yet available)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

OpenNest.Engine/Fill/FillLinear.cs

@@ -1,4 +1,3 @@
-using OpenNest.Engine.Strategies;
 using OpenNest.Geometry;
 using OpenNest.Math;
 using System.Collections.Generic;
@@ -250,7 +249,57 @@ namespace OpenNest.Engine.Fill
         private List<Part> TilePattern(Pattern basePattern, NestDirection direction, PartBoundary[] boundaries)
         {
             var copyDistance = FindPatternCopyDistance(basePattern, direction, boundaries);
-            return FillHelpers.Tile(basePattern.Parts, WorkArea, copyDistance, direction, allowPartial: true);
+
+            if (copyDistance <= 0)
+                return new List<Part>();
+
+            var dim = GetDimension(basePattern.BoundingBox, direction);
+            var start = GetStart(basePattern.BoundingBox, direction);
+            var limit = GetLimit(direction);
+
+            var estimatedCopies = (int)((limit - start - dim) / copyDistance);
+            var result = new List<Part>(estimatedCopies * basePattern.Parts.Count);
+
+            var count = 1;
+
+            while (true)
+            {
+                var nextPos = start + copyDistance * count;
+
+                if (nextPos + dim > limit + Tolerance.Epsilon)
+                    break;
+
+                var offset = MakeOffset(direction, copyDistance * count);
+
+                foreach (var part in basePattern.Parts)
+                    result.Add(part.CloneAtOffset(offset));
+
+                count++;
+            }
+
+            // For multi-part patterns, try to place individual parts from the
+            // next copy that didn't fit as a whole. This handles cases where
+            // e.g. a 2-part pair only partially fits — one part may still be
+            // within the work area even though the full pattern exceeds it.
+            if (basePattern.Parts.Count > 1)
+            {
+                var offset = MakeOffset(direction, copyDistance * count);
+
+                foreach (var basePart in basePattern.Parts)
+                {
+                    var part = basePart.CloneAtOffset(offset);
+
+                    if (part.BoundingBox.Right <= WorkArea.Right + Tolerance.Epsilon &&
+                        part.BoundingBox.Top <= WorkArea.Top + Tolerance.Epsilon &&
+                        part.BoundingBox.Left >= WorkArea.Left - Tolerance.Epsilon &&
+                        part.BoundingBox.Bottom >= WorkArea.Bottom - Tolerance.Epsilon)
+                    {
+                        result.Add(part);
+                    }
+                }
+            }
+
+            return result;
         }
 
         /// <summary>