cli: make bundled help self-describing

packages/inbox-runtime/internal/cli/inbox/reply.go

@@ -27,6 +27,14 @@ func newReplyCmd(root *rootOptions) *cobra.Command {
 	cmd := &cobra.Command{
 		Use:   "reply",
 		Short: "Reply inside an existing thread",
+		Long: helpLong(
+			"Use reply to append a directed answer, control note, or follow-up message to an existing thread.",
+			"Leaders usually use reply or orch answer when a worker is blocked.",
+			"Workers may also use reply for non-terminal coordination that should stay inside the same thread history.",
+			"reply is for one existing thread; use send when you need to create a new thread.",
+		),
+		Example: `  inbox --db .agents/coord.db reply --from leader --to worker-a --thread thr_123 --summary "Use stdout" --body "Use stdout for MVP."
+  inbox --db .agents/coord.db reply --from leader --to worker-a --thread thr_123 --kind control --summary "Proceed with option A" --payload-json '{"decision":"option_a"}'`,
 		RunE: func(cmd *cobra.Command, args []string) error {
 			ctx := cmd.Context()