Change if-else to switch statement

[digitalghost-dev]

For cleaner syntax, change the large if-else block in cli.go to a switch statement.

Switching to a switch statement would improve:
• Readability — Cleaner and easier to scan than deeply nested if-else blocks
• Maintainability — Simpler to add new cases or rearrange existing ones
• Go idiomatic style — switch is the preferred control structure for branching in Go when dealing with multiple conditions based on a single value

This change is purely structural and shouldn’t affect functionality.