Fix ci-bonsai-daily: reconnect Cost/IfcGit tool interfaces (TestImplementsTool)

Two TestImplementsTool failures on v0.8.0:

- test_cost.py: Cost could not be instantiated because
  core.tool.Cost declared abstract get_direct_cost_item_products, which
  tool.cost.Cost never implements. The method is dead (zero call sites;
  get_cost_item_products(is_deep=False) already covers the 'direct'
  case), so remove the abstract declaration.
- test_ifcgit.py: tool.ifcgit.IfcGit was not declared as a subclass of
  its core.tool.IfcGit interface (unlike every sibling tool class), so
  the isinstance check failed. Add the base class (and the
  bonsai.core.tool import it needs). All 50 interface methods are
  already implemented on the concrete class.

No behaviour change. Verified in headless Blender: isinstance(Cost(), core.tool.Cost) and isinstance(IfcGit(), core.tool.IfcGit) both True (were TypeError / False); repo abstract-vs-impl diff confirms all IfcGit abstracts are implemented.

This change was made with the assistance of an AI tool.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/bonsai/bonsai/core/tool.py

@@ -254,7 +254,6 @@ class Cost:
     def get_cost_schedule(cls, cost_schedule): pass
     def get_cost_value_attributes(cls): pass
     def get_cost_value_unit_component(cls): pass
-    def get_direct_cost_item_products(cls): pass
     def get_highlighted_cost_item(cls): pass
     def get_products(cls, related_object_type): pass
     def get_schedule_cost_items(cls, cost_schedule): pass

src/bonsai/bonsai/tool/ifcgit.py

@@ -29,6 +29,7 @@ from typing import TYPE_CHECKING, Any, Union
 
 import bpy
 
+import bonsai.core.tool
 import bonsai.tool as tool
 from bonsai.bim import import_ifc
 from bonsai.bim.ifc import IfcStore
@@ -50,7 +51,7 @@ if TYPE_CHECKING:
     from bonsai.bim.module.ifcgit.prop import IfcGitProperties
 
 
-class IfcGit:
+class IfcGit(bonsai.core.tool.IfcGit):
     STEP_IDS = dict[str, set[int]]
 
     @classmethod