refactor: Further condense delegation methods across components

Update component call sites to use target components directly instead
of routing through DiffStix wrapper methods, reducing indirection.

Changes:
- Updated markdown_generator.py: Call _hierarchy_builder.get_groupings() directly
- Updated json_generator.py: Call _hierarchy_builder.get_groupings() directly
- Updated change_detector.py: Call _contributor_tracker.update_contributors() directly

- Removed internal-only wrapper methods from diff_stix.py:
  - load_domain() - only called internally, now uses _data_loader directly
  - parse_extra_data() - only called by data_loader component

- Kept public API wrapper methods for backward compatibility:
  - get_groupings(), update_contributors(), get_parent_stix_object()
  - placard(), get_contributor_section(), get_statistics_section()
  - get_markdown_string(), get_layers_dict(), get_changes_dict()
  - find_technique_mitigation_changes(), find_technique_detection_changes()

Impact:
- diff_stix.py: 556 → 532 lines (4.3% reduction, 24 lines removed)
- Total from original: 1,462 → 532 lines (63.6% reduction, 930 lines removed)
- Reduced coupling between components
- Clearer component boundaries and responsibilities
- Maintained backward compatibility for public API

Author: claude

mitreattack/diffStix/core/change_detector.py

@@ -118,7 +118,7 @@ def categorize_version_change(
             - new_version: The new version
         """
         # Verify if there are new contributors on the object
-        self.diff_stix.update_contributors(old_object=old_obj, new_object=new_obj)
+        self.diff_stix._contributor_tracker.update_contributors(old_object=old_obj, new_object=new_obj)
 
         old_version = get_attack_object_version(old_obj)
         new_version = get_attack_object_version(new_obj)

mitreattack/diffStix/core/diff_stix.py

@@ -378,16 +378,6 @@ def find_technique_detection_changes(self, new_stix_obj: dict, domain: str):
         """
         return self._change_detector.find_technique_detection_changes(new_stix_obj, domain)
 
-    def load_domain(self, domain: str):
-        """Load data from directory according to domain.
-
-        Parameters
-        ----------
-        domain : str
-            An ATT&CK domain from the following list ["enterprise-attack", "mobile-attack", "ics-attack"]
-        """
-        return self._data_loader.load_domain(domain)
-
     def get_datastore_from_mitre_cti(self, domain: str, datastore_version: str) -> stix2.MemoryStore:
         """Load data from MITRE CTI repo according to domain.
 
@@ -408,20 +398,6 @@ def get_datastore_from_mitre_cti(self, domain: str, datastore_version: str) -> s
             self._data_loader = DataLoader(self)
         return self._data_loader.get_datastore_from_mitre_cti(domain, datastore_version)
 
-    def parse_extra_data(self, data_store: stix2.MemoryStore, domain: str, datastore_version: str):
-        """Parse STIX datastore objects and relationships.
-
-        Parameters
-        ----------
-        data_store : stix2.MemoryStore
-            STIX MemoryStore object representing an ATT&CK domain.
-        domain : str
-            An ATT&CK domain from the following list ["enterprise-attack", "mobile-attack", "ics-attack"]
-        datastore_version : str
-            The comparative version of the ATT&CK datastore. Choices are either "old" or "new".
-        """
-        return self._data_loader.parse_extra_data(data_store, domain, datastore_version)
-
     def update_contributors(self, old_object: Optional[dict], new_object: dict):
         """Update contributors list if new object has contributors.
 

mitreattack/diffStix/formatters/json_generator.py

@@ -37,7 +37,7 @@ def generate(self) -> dict:
                 changes_dict[domain][object_type] = {}
 
                 for section, stix_objects in sections.items():
-                    groupings = self.diff_stix.get_groupings(
+                    groupings = self.diff_stix._hierarchy_builder.get_groupings(
                         object_type=object_type,
                         stix_objects=stix_objects,
                         section=section,

mitreattack/diffStix/formatters/markdown_generator.py

@@ -74,7 +74,7 @@ def generate(self) -> str:
                 for section, stix_objects in self.diff_stix.data["changes"][object_type][domain].items():
                     header = f"#### {section_headers[section]}"
                     if stix_objects:
-                        groupings = self.diff_stix.get_groupings(
+                        groupings = self.diff_stix._hierarchy_builder.get_groupings(
                             object_type=object_type,
                             stix_objects=stix_objects,
                             section=section,