Refactor depth reference handling and cleanup

- Unified reference depth calculation to use a single implementation in common/depth.py.
- Removed server-side reference depth computation and adjusted depth.json to only include image_size and intrinsics.
- Updated depth texture handling to ignore transparent, invalid, and non-positive pixels when calculating reference depth.
- Changed reference depth calculation to use the 95th percentile of valid depth values.
- Adjusted depth direction fitting to return a flat direction when no samples are available.
- Removed cleanup threshold parameters from Cutout and related nodes, simplifying the interface.
- Updated tests to verify new reference depth logic and ensure compatibility with existing functionality.

tools/nodes/groups/image_cutout.py

@@ -2,7 +2,7 @@
 import bpy
 from anyimage.operators.cutout_tool.shape import NORMAL_REDUCTION_ATTRIBUTE_NAME
 from ..common.nodes import interface_socket, group_input, math_node, float_input, menu_switch, read_float_attribute, store_float_attribute, prepare_node_group
-from ..common.cutout import _extrude_layers, _island_cleanup, _offset_geometry_y, _remove_zero_thickness, _set_layer_y, _shade_output
+from ..common.cutout import _extrude_layers, _offset_geometry_y, _remove_zero_thickness, _set_layer_y, _shade_output
 
 
 NODE_GROUP_NAME = "O Image Cutout"
@@ -157,8 +157,6 @@ def build_image_cutout_group():
     interface_socket(group, 'Mode', 'INPUT', 'NodeSocketMenu')
     float_input(group, 'Thickness', 1.0, maximum=2.0).description = 'Control how much the surface bulges in Balloon mode. Zero removes the bulge.'
     float_input(group, 'Shell Thickness', 0.0, maximum=1.0, subtype='DISTANCE').description = 'Add thickness behind the original surface while keeping the front surface in place.'
-    options = group.interface.new_panel(name='Options', default_closed=True)
-    float_input(group, 'Cleanup Threshold', 0.0, parent=options)
     interface_socket(group, 'Geometry', 'OUTPUT', 'NodeSocketGeometry')
     controls = group_input(group.nodes, set())
     balloon = _build_balloon(group, controls.outputs['Geometry'], controls.outputs['Thickness'])
@@ -167,14 +165,6 @@ def build_image_cutout_group():
     group.links.new(balloon, choose.inputs['Balloon'])
     group.links.new(shell, choose.inputs['Shell'])
     geometry = choose.outputs[0]
-    planar_inputs = [link.to_socket for link in group.links if link.from_node.bl_idname == 'NodeGroupInput' and link.from_socket.name == 'Geometry']
-    base = group_input(group.nodes, {'Geometry', 'Cleanup Threshold'})
-    area = math_node(group.nodes, 'MULTIPLY')
-    area.inputs[1].default_value = 0.01
-    group.links.new(base.outputs['Cleanup Threshold'], area.inputs[0])
-    cleaned = _island_cleanup(group, base.outputs['Geometry'], area.outputs[0])
-    for target in planar_inputs:
-        group.links.new(cleaned, target)
     profile = read_float_attribute(group, 'o_balloon')
     amount = group_input(group.nodes, {'Thickness'})
     enabled = math_node(group.nodes, 'GREATER_THAN')