chore: import upstream snapshot with attribution

pkg/observability/observability.go

@@ -0,0 +1,46 @@
+package observability
+
+import (
+	"context"
+	"errors"
+	"log/slog"
+
+	"github.com/github/github-mcp-server/pkg/observability/metrics"
+)
+
+// Exporters bundles observability primitives (logger + metrics) for dependency injection.
+// The logger is Go's stdlib *slog.Logger — integrators provide their own slog.Handler.
+type Exporters interface {
+	Logger() *slog.Logger
+	Metrics(context.Context) metrics.Metrics
+}
+
+type exporters struct {
+	logger  *slog.Logger
+	metrics metrics.Metrics
+}
+
+// NewExporters creates an Exporters bundle. Pass a configured *slog.Logger
+// (with whatever slog.Handler you need) and a Metrics implementation.
+// Neither may be nil; use slog.New(slog.DiscardHandler) and metrics.NewNoopMetrics()
+// if logging or metrics are unwanted.
+func NewExporters(logger *slog.Logger, m metrics.Metrics) (Exporters, error) {
+	if logger == nil {
+		return nil, errors.New("logger must not be nil: use slog.New(slog.DiscardHandler) to discard logs")
+	}
+	if m == nil {
+		return nil, errors.New("metrics must not be nil: use metrics.NewNoopMetrics() to discard metrics")
+	}
+	return &exporters{
+		logger:  logger,
+		metrics: m,
+	}, nil
+}
+
+func (e *exporters) Logger() *slog.Logger {
+	return e.logger
+}
+
+func (e *exporters) Metrics(_ context.Context) metrics.Metrics {
+	return e.metrics
+}