Fix merged subchannel mesh fallout in tests, docs, and gold files Refs idaholab#32847

Author: kyriv1980

modules/combined/test/tests/subchannel_thm_coupling/3D.i

@@ -10,24 +10,14 @@ heated_length = 1.0
 ###################################################
 [TriSubChannelMesh]
   [subchannel]
-    type = SCMDetailedTriSubChannelMeshGenerator
+    type = SCMDetailedTriAssemblyMeshGenerator
     nrings = ${n_rings}
     n_cells = ${n_cells}
     flat_to_flat = ${inner_duct_in}
     heated_length = ${heated_length}
     pin_diameter = ${fuel_pin_diameter}
     pitch = ${fuel_pin_pitch}
   []
-
-  [fuel_pins]
-    type = SCMDetailedTriPinMeshGenerator
-    input = subchannel
-    nrings = ${n_rings}
-    n_cells = ${n_cells}
-    pin_diameter = ${fuel_pin_diameter}
-    heated_length = ${heated_length}
-    pitch = ${fuel_pin_pitch}
-  []
 []
 
 [AuxVariables]

modules/combined/test/tests/subchannel_thm_coupling/subchannel.i

@@ -17,7 +17,7 @@ heated_length = 1.0
 ###################################################
 [TriSubChannelMesh]
   [subchannel]
-    type = SCMTriSubChannelMeshGenerator
+    type = SCMTriAssemblyMeshGenerator
     nrings = ${n_rings}
     n_cells = ${n_cells}
     flat_to_flat = ${inner_duct_in}
@@ -29,15 +29,6 @@ heated_length = 1.0
     spacer_z = '0.0'
     spacer_k = '0.0'
   []
-
-  [fuel_pins]
-    type = SCMTriPinMeshGenerator
-    input = subchannel
-    nrings = ${n_rings}
-    n_cells = ${n_cells}
-    heated_length = ${heated_length}
-    pitch = ${fuel_pin_pitch}
-  []
 []
 
 [AuxVariables]

modules/subchannel/doc/content/source/meshgenerators/SCMQuadAssemblyMeshGenerator.md

@@ -0,0 +1,21 @@
+# SCMQuadAssemblyMeshGenerator
+
+!syntax description /Mesh/SCMQuadAssemblyMeshGenerator
+
+## Overview
+
+!! Intentional comment to provide extra spacing
+
+This mesh generator creates the 1D subchannel and pin meshes for a square lattice arrangement.
+The generated subdomains are named `subchannel` and `fuel_pins`.
+The center of the mesh is the origin.
+
+## Example Input File Syntax
+
+!listing /test/tests/problems/psbt/psbt_explicit.i block=QuadSubChannelMesh language=moose
+
+!syntax parameters /Mesh/SCMQuadAssemblyMeshGenerator
+
+!syntax inputs /Mesh/SCMQuadAssemblyMeshGenerator
+
+!syntax children /Mesh/SCMQuadAssemblyMeshGenerator

modules/subchannel/doc/content/source/postprocessors/SCMPinPowerPostprocessor.md

@@ -10,8 +10,8 @@ The user needs to specify a subchannel problem. Either a [QuadSubChannel1PhasePr
 
 ## Example Input File Syntax
 
-!listing /test/tests/SCMQuadPower/test.i block=Postprocessors language=moose
-!listing /test/tests/SCMTriPower/test.i block=Postprocessors language=moose
+!listing /test/tests/SCMQuadPower/test_with_pins.i block=Postprocessors language=moose
+!listing /test/tests/SCMTriPower/test_with_pins.i block=Postprocessors language=moose
 
 !syntax parameters /Postprocessors/SCMPinPowerPostprocessor