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/llm/openai.go

@@ -4,16 +4,19 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"log/slog"
 	"os"
+	"time"
 
 	openai "github.com/sashabaranov/go-openai"
 
 	coretypes "github.com/enmanuel/agents/pkg/llm"
+	"github.com/enmanuel/agents/shell/logger"
 )
 
 // NewOpenAIComplete returns a CompleteFunc backed by the OpenAI-compatible API.
 // Works with OpenAI, Ollama, vLLM, LMStudio — just change baseURL.
-func NewOpenAIComplete(apiKeyEnv, baseURL string) coretypes.CompleteFunc {
+func NewOpenAIComplete(apiKeyEnv, baseURL string, log *slog.Logger) coretypes.CompleteFunc {
 	return func(ctx context.Context, req coretypes.CompletionRequest) (coretypes.CompletionResponse, error) {
 		apiKey := os.Getenv(apiKeyEnv)
 		if apiKey == "" {
@@ -49,11 +52,24 @@ func NewOpenAIComplete(apiKeyEnv, baseURL string) coretypes.CompleteFunc {
 			openReq.Tools = toOpenAITools(req.Tools)
 		}
 
+		log.Info("llm_request",
+			"provider", "openai",
+			"model", req.Model,
+			"messages", len(req.Messages),
+			"tools", len(req.Tools),
+		)
+
+		start := time.Now()
 		resp, err := client.CreateChatCompletion(ctx, openReq)
 		if err != nil {
+			ms := time.Since(start).Milliseconds()
+			log.Error("llm_error", "provider", "openai", logger.FieldDurationMS, ms, "err", err)
 			return coretypes.CompletionResponse{}, fmt.Errorf("openai completion: %w", err)
 		}
+		ms := time.Since(start).Milliseconds()
+
 		if len(resp.Choices) == 0 {
+			log.Error("llm_error", "provider", "openai", logger.FieldDurationMS, ms, "err", "empty choices")
 			return coretypes.CompletionResponse{}, fmt.Errorf("openai: empty choices")
 		}
 
@@ -67,6 +83,17 @@ func NewOpenAIComplete(apiKeyEnv, baseURL string) coretypes.CompleteFunc {
 			})
 		}
 
+		log.Info("llm_response",
+			"provider", "openai",
+			"model", req.Model,
+			logger.FieldDurationMS, ms,
+			logger.FieldTokensUsed, resp.Usage.TotalTokens,
+			"input_tokens", resp.Usage.PromptTokens,
+			"output_tokens", resp.Usage.CompletionTokens,
+			"tool_calls", len(toolCalls),
+			"finish_reason", string(choice.FinishReason),
+		)
+
 		return coretypes.CompletionResponse{
 			Content:      choice.Message.Content,
 			ToolCalls:    toolCalls,