Fixed compilation error where Infrastructure layer was referencing API layer (ColaFlow.API.Hubs). This violated the dependency inversion principle and Clean Architecture layering rules. Changes: - Moved McpNotificationHub from ColaFlow.API/Hubs to ColaFlow.Modules.Mcp.Infrastructure/Hubs - Updated McpNotificationHub to inherit directly from Hub instead of BaseHub - Copied necessary helper methods (GetCurrentUserId, GetCurrentTenantId, GetTenantGroupName) to avoid cross-layer dependency - Updated McpNotificationService to use new namespace (ColaFlow.Modules.Mcp.Infrastructure.Hubs) - Updated Program.cs to import new Hub namespace - Updated McpNotificationServiceTests to use new namespace - Kept BaseHub in API layer for ProjectHub and NotificationHub Architecture Impact: - Infrastructure layer no longer depends on API layer - Proper dependency flow: API -> Infrastructure -> Application -> Domain - McpNotificationHub is now properly encapsulated within the MCP module 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <noreply@anthropic.com>