feat: [AG-101] migrate to official mcp go sdk

[dan-arpino]

Summary

Migrate from github.com/mark3labs/mcp-go v0.31.0 to the official github.com/modelcontextprotocol/go-sdk v1.2.0.

Key Changes

• Server Creation: Updated to use mcp.NewServer() with Implementation struct instead of server.NewMCPServer()
• Transport Handling:
  • Stdio: Changed to mcpServer.Run(ctx, &mcp.StdioTransport{})
  • SSE: Changed to mcp.NewSSEHandler(func(r *http.Request) *mcp.Server {...})
• Tool Handlers: Updated signatures to accept *mcp.CallToolRequest (pointer)
• Argument Extraction: Replaced request.GetArguments() with json.Unmarshal from request.Params.Arguments
• Client Info: Updated to iterate through server.Sessions() instead of context extraction
• Logging: Changed to session-based ss.Log() instead of SendNotificationToAllClients
• Helper Functions: Added NewToolResultText(), NewToolResultError(), getRequestArguments(), ClientInfoFromSession()

Files Modified

File	Description
go.mod, go.sum	Updated dependency
internal/mcp/llm_binding.go	Server creation, transport handling
internal/mcp/tools.go	Tool handlers, argument extraction
internal/mcp/utils.go	Helper functions
internal/logging/logger.go	Session-based logging
internal/trust/trust.go	Tool result creation
pkg/mcp/main.go	Entry point updates
internal/mcp/*_test.go	Updated tests for new SDK
internal/mcp/integration_test.go	New integration tests
MCP_SDK_MIGRATION_NOTES.md	Migration documentation

Test plan

• All existing unit tests pass with new SDK
• MCP spec conformance tests updated and passing
• New integration tests for SDK migration
• Manual testing of stdio transport
• Manual testing of SSE transport
• Test with actual MCP clients (Cursor, Claude Desktop)