Shape.OffsetOutward produces inward offsets for certain rotated polygons,
causing geometry-aware copy distances to be too small and placing
overlapping parts. Root cause is in the offset winding direction
detection — this commit adds safety nets while that is investigated.
- FillLinear.FillGrid: detect bbox overlaps after geometry-aware tiling,
fall back to bbox-based spacing when overlaps found
- FillExtents.RepeatColumns: detect overlaps after Compactor computes
copy distance, fall back to columnWidth + spacing
- PairFiller/StripeFiller remnant fills: use FillLinear directly instead
of spawning full engine pipeline (avoids strategies with the bug)
- Add PairOverlapDiagnosticTests reproducing the issue
- MCP config: use shadow-copy wrapper for dev hot-reload
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
