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/tests/unit/services/memory/mcp/test_tools.py

@@ -358,10 +358,12 @@ class TestMemoryToolDefinition:
         )
 
         # Valid args
-        validated = tool.validate_args({
-            "memory_type": "working",
-            "content": "Test content",
-        })
+        validated = tool.validate_args(
+            {
+                "memory_type": "working",
+                "content": "Test content",
+            }
+        )
         assert isinstance(validated, RememberArgs)
 
         # Invalid args
@@ -417,4 +419,6 @@ class TestToolDefinitions:
         """All tool schemas should have properties defined."""
         for name, tool in MEMORY_TOOL_DEFINITIONS.items():
             schema = tool.to_mcp_format()
-            assert "properties" in schema["inputSchema"], f"Tool {name} missing properties"
+            assert "properties" in schema["inputSchema"], (
+                f"Tool {name} missing properties"
+            )