Apply pre-commit linting fixes

Fix trailing whitespace and end-of-file issues across codebase.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

stack_orchestrator/build/fetch_containers.py

@@ -79,7 +79,7 @@ def _find_latest(candidate_tags: List[str]):
     return sorted_candidates[-1]
 
 
-def _filter_for_platform(container: str, 
+def _filter_for_platform(container: str,
                          registry_info: RegistryInfo,
                          tag_list: List[str]) -> List[str] :
     filtered_tags = []