Refactor DemoCommand to Use Task-Based Step System

[armanist]

Refactor Shared\Commands\DemoCommand to implement a task-based steps system for generating demo data.

Each step should:

• Have a clear, human-readable message displayed in the progress bar.
• Encapsulate the action as a closure or callable executed sequentially.
• Ensure users, posts, and comments are generated in the correct order.
• Display task-focused progress instead of generic percentages.
• Improve the progress bar appearance to be more readable and visually appealing.

Acceptance Criteria:

The command executes all steps correctly in order:

• Create API module
• Create Web module
• Clean uploads & rebuild database
• Generate users
• Generate posts
• Generate comments