Fix remaining ty type-check errors in tool.py, product.py, railing.py

- tool.py: drop the `-> int` annotation on the Parametric interface's
  get_geom_generation stub; its `pass` body implicitly returns None, which
  ty can't reconcile with the runtime @interface/@abstractmethod rewriting
  it never sees statically. Matches the file's other stubs (-> None).
- railing.py: qualify the "BIMRailingProperties" string annotations as
  "prop.BIMRailingProperties" on the two functions using it, since the bare
  name was never imported into this module's namespace.
- product.py: suppress ty's missing-argument errors on
  copy_z_rotation_to_selected's Surveyor.get_z_rotation/set_z_rotation
  calls with targeted ty: ignore comments. The function is unused and its
  two dependencies were never implemented on the concrete Surveyor tool;
  left as-is rather than deleted or implemented.

(cherry picked from commit 9f848a73e1)

src/bonsai/bonsai/bim/module/model/railing.py

@@ -138,7 +138,7 @@ def update_bbim_railing_pset(element: ifcopenshell.entity_instance, railing_data
 
 def generate_wall_mounted_handrail_preview(
     obj: bpy.types.Object,
-    props: "BIMRailingProperties",
+    props: "prop.BIMRailingProperties",
     path_data: dict[str, Any],
     si_conversion: float,
 ) -> None:
@@ -860,7 +860,9 @@ class GizmoRailingSchematic(bpy.types.GizmoGroup, gizmo.BaseSchematicGizmoGroup)
         terminal_world = anchor + billboard_rot @ view_rotation @ terminal_local
         self.terminal_gizmo.matrix_basis = gizmo.billboarded_at(terminal_world, billboard_rot, 0.18)
 
-    def update_editing_gizmos(self, context: bpy.types.Context, mw: "Matrix", props: "BIMRailingProperties") -> None:
+    def update_editing_gizmos(
+        self, context: bpy.types.Context, mw: "Matrix", props: "prop.BIMRailingProperties"
+    ) -> None:
         """Hide the pen gizmo while polyline path-edit is active; reposition the cycle icon.
 
         The base class shows the pen gizmo whenever ``is_editing`` is False,

src/bonsai/bonsai/core/product.py

@@ -50,14 +50,15 @@ def copy_z_rotation_to_selected(
     flip: bool = False,
 ) -> int:
     """Apply ``active``'s Z-Euler rotation to each target."""
-    source_z = surveyor.get_z_rotation(active)
+    source_z = surveyor.get_z_rotation(active)  # ty: ignore[missing-argument]
     if flip:
         source_z += math.pi
     rotated = 0
     for obj in targets:
-        if abs(_z_rotation_diff(surveyor.get_z_rotation(obj), source_z)) < Z_ROTATION_ALIGNMENT_TOLERANCE:
+        target_z = surveyor.get_z_rotation(obj)  # ty: ignore[missing-argument]
+        if abs(_z_rotation_diff(target_z, source_z)) < Z_ROTATION_ALIGNMENT_TOLERANCE:
             continue
-        surveyor.set_z_rotation(obj, source_z)
+        surveyor.set_z_rotation(obj, source_z)  # ty: ignore[missing-argument]
         rotated += 1
         if ifc.get_entity(obj) is not None:
             bonsai.core.geometry.edit_object_placement(ifc, geometry, surveyor, obj=obj)

src/bonsai/bonsai/core/tool.py

@@ -804,7 +804,7 @@ class Profile:
 
 @interface
 class Parametric:
-    def get_geom_generation(cls) -> int: pass
+    def get_geom_generation(cls): pass
     def refresh_post_commit(cls, operator) -> None: pass