feat: mcp.Register for core.WithService — auto-discovers subsystems from Core

Co-Authored-By: Virgil <virgil@lethean.io>

pkg/mcp/register.go

@@ -0,0 +1,54 @@
+// SPDX-License-Identifier: EUPL-1.2
+
+package mcp
+
+import (
+	"context"
+
+	core "dappco.re/go/core"
+)
+
+// Register is the service factory for core.WithService.
+// Creates the MCP service, registers subsystems from other services
+// already in the Core conclave, and wires notifiers.
+//
+//	core.New(
+//	    core.WithService(agentic.Register),
+//	    core.WithService(monitor.Register),
+//	    core.WithService(brain.Register),
+//	    core.WithService(mcp.Register),
+//	)
+func Register(c *core.Core) core.Result {
+	// Collect subsystems from registered services
+	var subsystems []Subsystem
+	for _, name := range c.Services() {
+		r := c.Service(name)
+		if !r.OK {
+			continue
+		}
+		if sub, ok := r.Value.(Subsystem); ok {
+			subsystems = append(subsystems, sub)
+		}
+	}
+
+	svc, err := New(Options{
+		Subsystems: subsystems,
+	})
+	if err != nil {
+		return core.Result{Value: err, OK: false}
+	}
+
+	return core.Result{Value: svc, OK: true}
+}
+
+// OnStartup implements core.Startable — MCP is ready for tool calls.
+// Transport is NOT started here — the CLI command (mcp/serve) starts
+// the appropriate transport explicitly.
+func (s *Service) OnStartup(ctx context.Context) error {
+	return nil
+}
+
+// OnShutdown implements core.Stoppable — stops the MCP transport.
+func (s *Service) OnShutdown(ctx context.Context) error {
+	return s.Shutdown(ctx)
+}