feat: integrar structured logging en todos los componentes del shell

Se propaga *slog.Logger a todos los componentes impuros del shell:
- shell/bus/ — logs de subscribe, send, reply, timeout, unsubscribe
- shell/effects/ — duración y resultado de cada action ejecutada
- shell/llm/ (anthropic, openai, factory) — request/response con tokens, duración, fallback
- shell/memory/sqlite — open, save, recall, close con detalles
- shell/ssh/ — inicio, fin, errores y duración de comandos SSH
- tools/registry — registro, ejecución y errores de herramientas

Se usa el paquete shell/logger para field names consistentes (FieldDurationMS, FieldTokensUsed, etc.).
Cada componente recibe el logger por inyección de dependencias, sin globals.
Las firmas de New/FromConfig se actualizan para aceptar *slog.Logger.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

shell/bus/bus.go

@@ -4,6 +4,7 @@ package bus
 import (
 	"context"
 	"fmt"
+	"log/slog"
 	"sync"
 	"time"
 )
@@ -30,15 +31,18 @@ type Bus struct {
 	mu       sync.RWMutex
 	channels map[AgentID]chan AgentMessage
 
-	replyMu   sync.Mutex
-	replyChs  map[string]chan AgentMessage // taskID → one-shot reply channel
+	replyMu  sync.Mutex
+	replyChs map[string]chan AgentMessage // taskID → one-shot reply channel
+
+	logger *slog.Logger
 }
 
 // New creates a new Bus.
-func New() *Bus {
+func New(logger *slog.Logger) *Bus {
 	return &Bus{
 		channels: make(map[AgentID]chan AgentMessage),
 		replyChs: make(map[string]chan AgentMessage),
+		logger:   logger.With("component", "bus"),
 	}
 }
 
@@ -48,6 +52,7 @@ func (b *Bus) Subscribe(id AgentID) <-chan AgentMessage {
 	defer b.mu.Unlock()
 	ch := make(chan AgentMessage, 64)
 	b.channels[id] = ch
+	b.logger.Info("bus_subscribe", "agent", id)
 	return ch
 }
 
@@ -57,12 +62,15 @@ func (b *Bus) Send(msg AgentMessage) error {
 	ch, ok := b.channels[msg.To]
 	b.mu.RUnlock()
 	if !ok {
+		b.logger.Warn("bus_not_found", "to", msg.To, "from", msg.From, "kind", msg.Kind)
 		return fmt.Errorf("agent %q not registered on bus", msg.To)
 	}
 	select {
 	case ch <- msg:
+		b.logger.Debug("bus_send", "from", msg.From, "to", msg.To, "kind", msg.Kind)
 		return nil
 	default:
+		b.logger.Warn("bus_queue_full", "to", msg.To, "from", msg.From, "kind", msg.Kind)
 		return fmt.Errorf("agent %q message queue full", msg.To)
 	}
 }
@@ -86,6 +94,8 @@ func (b *Bus) SendAndWait(ctx context.Context, msg AgentMessage, taskID string,
 		return AgentMessage{}, err
 	}
 
+	b.logger.Debug("bus_send_and_wait", "task", taskID, "to", msg.To, "timeout", timeout)
+
 	timer := time.NewTimer(timeout)
 	defer timer.Stop()
 
@@ -93,6 +103,7 @@ func (b *Bus) SendAndWait(ctx context.Context, msg AgentMessage, taskID string,
 	case reply := <-ch:
 		return reply, nil
 	case <-timer.C:
+		b.logger.Warn("bus_timeout", "task", taskID, "to", msg.To, "timeout", timeout)
 		return AgentMessage{}, fmt.Errorf("task %s: delegation timeout after %s", taskID, timeout)
 	case <-ctx.Done():
 		return AgentMessage{}, ctx.Err()
@@ -109,8 +120,10 @@ func (b *Bus) Reply(taskID string, msg AgentMessage) error {
 	if ok {
 		select {
 		case ch <- msg:
+			b.logger.Debug("bus_reply", "task", taskID, "from", msg.From)
 			return nil
 		default:
+			b.logger.Warn("bus_reply_full", "task", taskID)
 			return fmt.Errorf("reply channel full for task %s", taskID)
 		}
 	}
@@ -125,5 +138,6 @@ func (b *Bus) Unsubscribe(id AgentID) {
 	if ch, ok := b.channels[id]; ok {
 		close(ch)
 		delete(b.channels, id)
+		b.logger.Info("bus_unsubscribe", "agent", id)
 	}
 }