[Feature]: Add command cooldown system

[youngcoder45]

Problem / use case

Implement a cooldown system to prevent users from spamming commands.
Context:
Without cooldowns, users can spam commands, which can cause performance issues and poor user experience.

Proposed solution

1. Identify where commands are executed
2. Create a cooldown map (userId → timestamp)
3. Before executing a command:
   • Check if user is within cooldown period
4. If yes:
   • Return cooldown message
5. If no:
   • Execute command and update timestamp
6. Make cooldown duration configurable

Alternatives considered

• Commands cannot be spammed
• Users receive a cooldown message
• Cooldown resets after defined time

Additional context

Files / areas to look at:

• Command handler logic
• User interaction handling

Checklist:

• The scope is reasonable for intermediate contributors.
• Acceptance criteria are clear and testable.
• Relevant pointers/links are included.

Checklist

• I searched existing issues before opening this.

[HyScript7]

Can't this simply be implemented using discord.py's builtin cooldown decorator with a member bucket type?