refactor(safety): apply consistent formatting across services and tests

Improved code readability and uniformity by standardizing line breaks, indentation, and inline conditions across safety-related services, models, and tests, including content filters, validation rules, and emergency controls.

backend/tests/services/mcp/test_client_manager.py

@@ -14,7 +14,6 @@ from app.services.mcp.client_manager import (
     shutdown_mcp_client,
 )
 from app.services.mcp.config import MCPConfig, MCPServerConfig
-from app.services.mcp.connection import ConnectionState
 from app.services.mcp.exceptions import MCPServerNotFoundError
 from app.services.mcp.registry import MCPServerRegistry
 from app.services.mcp.routing import ToolInfo, ToolResult