Integrate email notifications into signup and login (#38)

backend/product/go.mod

@@ -69,13 +69,17 @@ require (
 	go.opentelemetry.io/otel/trace v1.44.0 // indirect
 	go.uber.org/multierr v1.10.0 // indirect
 	go.yaml.in/yaml/v3 v3.0.5 // indirect
+	golang.org/x/net v0.58.0 // indirect
 	golang.org/x/sync v0.22.0 // indirect
 	golang.org/x/sys v0.47.0 // indirect
 	golang.org/x/text v0.41.0 // indirect
-	google.golang.org/protobuf v1.36.11 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20260526163538-3dc84a4a5aaa // indirect
 )
 
+replace git.sendico.io/tech/sxchnge/shared => ../shared
+
 require (
+	git.sendico.io/tech/sxchnge/notifications/interface v0.0.0
 	git.sendico.io/tech/sxchnge/shared v0.0.0
 	github.com/go-chi/chi/v5 v5.3.2
 	github.com/go-chi/cors v1.2.2
@@ -89,8 +93,10 @@ require (
 	go.mongodb.org/mongo-driver/v2 v2.9.0
 	go.uber.org/zap v1.28.0
 	golang.org/x/crypto v0.56.0
+	google.golang.org/grpc v1.83.2
+	google.golang.org/protobuf v1.36.12
 	gopkg.in/yaml.v3 v3.0.1
 	moul.io/chizap v1.0.3
 )
 
-replace git.sendico.io/tech/sxchnge/shared => ../shared
+replace git.sendico.io/tech/sxchnge/notifications/interface => ../notifications/interface