feat(capability/mcp): MCP 客户端（stdlib JSON-RPC over stdio/SSE）+ Registry 自动注册/Unregister（registry 增 Remove）

internal/capability/mcp/registry.go

@@ -0,0 +1,81 @@
+package mcp
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"log/slog"
+	"sync"
+
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/capability/registry"
+)
+
+// Registry connects an MCP client and auto-registers its discovered tools into
+// the shared capability registry, making them available to every character.
+type Registry struct {
+	reg    *registry.Registry
+	mcp    *Client
+	log    *slog.Logger
+	mu     sync.Mutex
+	names  []string
+	closed bool
+}
+
+// NewRegistry builds a Registry that registers cfg's tools into reg. Options
+// apply to the underlying Client (logger, injected transport). It is named
+// NewRegistry rather than New because this package already exports New for
+// Client.
+func NewRegistry(reg *registry.Registry, cfg MCPConfig, opts ...Option) *Registry {
+	c := New(cfg, opts...)
+	return &Registry{reg: reg, mcp: c, log: c.log}
+}
+
+// Register connects the MCP server, discovers its tools, and registers each one
+// into the underlying registry.
+func (r *Registry) Register(ctx context.Context) error {
+	if r.reg == nil {
+		return fmt.Errorf("mcp registry: nil registry")
+	}
+	if err := r.mcp.Connect(ctx); err != nil {
+		return fmt.Errorf("mcp registry %q: %w", r.mcp.cfg.Name, err)
+	}
+	tools, err := r.mcp.DiscoverTools(ctx)
+	if err != nil {
+		return fmt.Errorf("mcp registry %q: %w", r.mcp.cfg.Name, err)
+	}
+
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	if r.closed {
+		return fmt.Errorf("mcp registry %q: %w", r.mcp.cfg.Name, ErrClosed)
+	}
+	for _, t := range tools {
+		if err := r.reg.RegisterTool(t); err != nil {
+			return fmt.Errorf("mcp register %q: %w", t.Name(), err)
+		}
+		r.names = append(r.names, t.Name())
+	}
+	r.log.Info("mcp tools registered", "name", r.mcp.cfg.Name, "count", len(tools))
+	return nil
+}
+
+// Unregister removes every tool this registry previously registered and closes
+// the underlying client. It is safe to call multiple times.
+func (r *Registry) Unregister(ctx context.Context) error {
+	r.mu.Lock()
+	names := r.names
+	r.names = nil
+	r.closed = true
+	r.mu.Unlock()
+
+	var errs error
+	for _, name := range names {
+		if err := r.reg.Remove(name); err != nil && !errors.Is(err, registry.ErrNotFound) {
+			errs = errors.Join(errs, fmt.Errorf("mcp unregister %q: %w", name, err))
+		}
+	}
+	if err := r.mcp.Close(); err != nil {
+		errs = errors.Join(errs, fmt.Errorf("mcp close %q: %w", r.mcp.cfg.Name, err))
+	}
+	return errs
+}