Add comprehensive MCP tool loading implementation plan

Created FUTURE-MCP.md with complete roadmap for integrating Model Context Protocol (MCP) server tool loading into ConfigLoader system.

Key Features Planned:
- Seamless integration with existing tool loading mechanisms
- Support for multiple MCP transport types (stdio, SSE, WebSocket, HTTP)
- MCPClient, MCPToolWrapper, and MCPServerRegistry architecture
- Enhanced ToolConfigLoader with MCP support
- Production-ready error handling and security features

Configuration Integration:
- MCP servers configurable at agent level
- Multiple tool loading patterns (specific tools, all tools from server)
- Consistent with existing configuration schema patterns
- No breaking changes to current ToolConfigLoader API

Implementation Phases:
1. Core MCP integration with stdio transport
2. Enhanced transport support for all MCP connection types
3. Advanced tool management with hot reloading and caching
4. Production features with monitoring and security hardening

Security and Reliability:
- Server validation and allowlisting
- Input/output sanitization and validation
- Resource limits and timeout management
- Automatic reconnection with exponential backoff
- Graceful degradation for server unavailability

Future-proof architecture supporting tool composition, dynamic schema generation, and marketplace integration. Ready for implementation when MCP integration is prioritized.

Author: vawsgit