feat: add OpenTelemetry tracing

api/main.go

@@ -15,6 +15,7 @@ import (
 	"terminalShop/pkg/auth"
 	"terminalShop/pkg/config"
 	"terminalShop/pkg/database"
+	"terminalShop/pkg/observability"
 )
 
 const version = "v0.1.0"
@@ -45,6 +46,17 @@ func main() {
 		log.Fatalf("Failed to seed database: %v", err)
 	}
 
+	otlpEndpoint := os.Getenv("OTLP_ENDPOINT")
+	if otlpEndpoint == "" {
+		otlpEndpoint = "tempo:4318"
+	}
+	shutdown, err := observability.InitTracing(context.Background(), "terminalshop-api", otlpEndpoint)
+	if err != nil {
+		log.Printf("tracing init failed (non-fatal): %v", err)
+	} else {
+		defer shutdown(context.Background())
+	}
+
 	// Init JWT manager (same secret + duration as SSH server)
 	jwtManager := auth.NewJWTManager(cfg.JWTSecret, 30*time.Minute)