adding more nodes

docs/nodes/Scan Line Reorder.md

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+# Scan Line Reorder
+
+Fix scan line ordering artifacts from meander (serpentine) scanning, interlacing, or inverted scan direction. Equivalent to Gwyddion's reorder.c module.
+
+## Inputs
+
+| Name | Type | Required | Description |
+|------|------|----------|-------------|
+| field | DATA_FIELD | Yes | Input field with scan line artifacts |
+
+## Outputs
+
+| Name | Type | Description |
+|------|------|-------------|
+| result | DATA_FIELD | Field with corrected scan line order |
+
+## Controls
+
+| Name | Type | Default | Description |
+|------|------|---------|-------------|
+| operation | dropdown | reverse_odd | Operation: reverse_odd, reverse_even, deinterlace_odd, deinterlace_even, flip_vertical |
+
+## Notes
+
+- **reverse_odd / reverse_even**: Reverse alternate rows to correct meander (serpentine/boustrophedon) scanning. Most SPM controllers scan left-to-right on odd lines and right-to-left on even lines; reversing odd rows fixes this.
+- **deinterlace_odd / deinterlace_even**: Keep only odd or even rows and stretch to fill the original height. Useful when alternate scan lines were acquired under different conditions.
+- **flip_vertical**: Reverse the row order (top becomes bottom). Useful when the scan direction is inverted.
+- Apply this node before Line Correction for best results.