`/ban` command

### 📌 Feature Summary

`/ban` command for Moderators

### 💡 Motivation

`/ban` command for Moderators so that they can ban people who violate server rules

### 🧩 Suggested Implementation

_No response_

### 🧠 Estimated Complexity

Medium (Multiple file changes, some logic updates)

### 🔗 Related Issues / PRs

_No response_

### 🧠 Additional Notes

_No response_