Function validateWorktreeSlug

src/utils/worktree.ts:70–91

(slug: string)

 * (git commands, hook execution, chdir).
 */
export function validateWorktreeSlug(slug: string): void {
  if (slug.length > MAX_WORKTREE_SLUG_LENGTH) {
    throw new Error(
      `Invalid worktree name: must be ${MAX_WORKTREE_SLUG_LENGTH} characters or fewer (got ${slug.length})`,
    )
  }
  // Leading or trailing `/` would make path.join produce an absolute path
  // or a dangling segment. Splitting and validating each segment rejects
  // both (empty segments fail the regex) while allowing `user/feature`.
  for (const segment of slug.split('/')) {
    if (segment === '.' || segment === '..') {
      throw new Error(
        `Invalid worktree name "${slug}": must not contain "." or ".." path segments`,
      )
    }
    if (!VALID_WORKTREE_SLUG_SEGMENT.test(segment)) {
      throw new Error(
        `Invalid worktree name "${slug}": each "/"-separated segment must be non-empty and contain only letters, digits, dots, underscores, and dashes`,
      )
    }
  }
}

// Helper function to create directories recursively
async function mkdirRecursive(dirPath: string): Promise<void> {