adding more nodes

docs/nodes/Mutual Crop.md

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+# Mutual Crop
+
+Align two images using FFT cross-correlation and crop both to their overlapping region. Useful for comparing images acquired at different times or with slight position offsets. Equivalent to Gwyddion's mcrop.c module.
+
+## Inputs
+
+| Name | Type | Required | Description |
+|------|------|----------|-------------|
+| field_a | DATA_FIELD | Yes | First input field |
+| field_b | DATA_FIELD | Yes | Second input field |
+
+## Outputs
+
+| Name | Type | Description |
+|------|------|-------------|
+| cropped_a | DATA_FIELD | Field A cropped to the overlapping region |
+| cropped_b | DATA_FIELD | Field B cropped to the overlapping region |
+
+## Controls
+
+This node has no user-adjustable controls. Alignment is fully automatic.
+
+## Notes
+
+- Both fields are zero-padded to a common shape, mean-subtracted, and cross-correlated in the frequency domain to find the optimal shift.
+- The overlap region is computed from the detected shift; both output fields are cropped to identical pixel dimensions.
+- If no valid overlap is found (e.g. completely non-overlapping images), the original fields are returned unchanged.
+- Physical dimensions (xreal, yreal) of the outputs are updated to reflect the cropped size using field_a's pixel spacing.