Bug: wait rejects valid multi-digit integers #8

Problem

The wait command is intended to accept an integer delay, but valid multi-digit values are currently rejected. This makes the command fail for inputs that should be accepted.

Specification

Fix wait so it accepts valid integer arguments consistently.

Acceptance criteria:

• Single-digit and multi-digit integer delays are accepted.
• Variable-expanded integer values are accepted.
• Invalid, empty, or multi-argument inputs still fail with a clear error message.
• The command's user-facing contract remains a single integer argument.

Motivation

This is a small correctness issue in an existing built-in command and is well-scoped for a bugfix contribution.