chore: import upstream snapshot with attribution

internal/cmdutil/groups.go

@@ -0,0 +1,18 @@
+// Copyright (c) 2026 Lark Technologies Pte. Ltd.
+// SPDX-License-Identifier: MIT
+
+package cmdutil
+
+import "github.com/spf13/cobra"
+
+// DeprecatedGroupID is the cobra GroupID that marks a backward-compatibility
+// command — one kept alive for users whose skill predates a refactor. Service
+// registration assigns it (e.g. the sheets pre-refactor aliases); both --help
+// rendering and unknown-subcommand suggestions read it to separate these
+// aliases from the current commands.
+const DeprecatedGroupID = "deprecated"
+
+// IsDeprecatedCommand reports whether c was tagged into the deprecated group.
+func IsDeprecatedCommand(c *cobra.Command) bool {
+	return c != nil && c.GroupID == DeprecatedGroupID
+}