style(memory): apply ruff formatting and linting fixes

Auto-fixed linting errors and formatting issues:
- Removed unused imports (F401): pytest, Any, AnalysisType, MemoryType, OutcomeType
- Removed unused variable (F841): hooks variable in test
- Applied consistent formatting across memory service and test files

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

backend/app/services/memory/integration/context_source.py

@@ -321,10 +321,7 @@ class MemoryContextSource:
             min_confidence=min_relevance,
         )
 
-        return [
-            MemoryContext.from_semantic_memory(fact, query=query)
-            for fact in facts
-        ]
+        return [MemoryContext.from_semantic_memory(fact, query=query) for fact in facts]
 
     async def _fetch_procedural(
         self,