feat: user service

user/internal/ports/errors.go

@@ -0,0 +1,31 @@
+// Package ports defines the storage-agnostic boundaries used by the user
+// service.
+package ports
+
+import (
+	"errors"
+	"fmt"
+)
+
+var (
+	// ErrNotFound reports that a requested source-of-truth record does not
+	// exist in the dependency behind the port.
+	ErrNotFound = errors.New("ports: record not found")
+
+	// ErrConflict reports that a create or update cannot be applied because the
+	// dependency state conflicts with the requested mutation.
+	ErrConflict = errors.New("ports: conflict")
+
+	// ErrInvalidPageToken reports that a supplied pagination token cannot be
+	// decoded or does not match the expected filter set.
+	ErrInvalidPageToken = errors.New("ports: invalid page token")
+)
+
+var (
+	// ErrRaceNameConflict reports that a mutation specifically failed because a
+	// race-name lookup or canonical reservation is already owned by another
+	// user. The sentinel still matches ErrConflict via errors.Is so callers can
+	// preserve the stable public conflict semantics while collecting more
+	// precise observability.
+	ErrRaceNameConflict = fmt.Errorf("%w: race name conflict", ErrConflict)
+)