feat(cli): add walkCommandTree and formatCommandTree helpers

packages/cli/src/command-tree.ts

@@ -0,0 +1,35 @@
+import type { Command } from '@commander-js/extra-typings';
+
+export interface CommandTreeNode {
+  name: string;
+  description: string;
+  aliases: string[];
+  children: CommandTreeNode[];
+}
+
+export function walkCommandTree(command: Command): CommandTreeNode {
+  return {
+    name: command.name(),
+    description: command.description(),
+    aliases: command.aliases(),
+    children: command.commands.map((child) => walkCommandTree(child as Command)),
+  };
+}
+
+export function formatCommandTree(node: CommandTreeNode): string {
+  const lines: string[] = [];
+  appendNode(node, 0, lines);
+  return `${lines.join('\n')}\n`;
+}
+
+function appendNode(node: CommandTreeNode, depth: number, lines: string[]): void {
+  const indent = '  '.repeat(depth);
+  const aliasPart = node.aliases.length > 0 ? ` (${node.aliases.join(', ')})` : '';
+  const descriptionPart = node.description.length > 0 ? ` - ${node.description}` : '';
+  lines.push(`${indent}${node.name}${aliasPart}${descriptionPart}`);
+
+  const sortedChildren = [...node.children].sort((a, b) => a.name.localeCompare(b.name));
+  for (const child of sortedChildren) {
+    appendNode(child, depth + 1, lines);
+  }
+}