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_registry.py

@@ -4,7 +4,7 @@ Tests for MCP Server Registry
 
 import pytest
 
-from app.services.mcp.config import MCPConfig, MCPServerConfig, TransportType
+from app.services.mcp.config import MCPConfig, MCPServerConfig
 from app.services.mcp.exceptions import MCPServerNotFoundError
 from app.services.mcp.registry import (
     MCPServerRegistry,