Function deleteKeyValue

deleteKeyValue(namespace, key): Promise<void>
Removes a specific key-value pair from storage.

Permanently deletes a key and its associated value from the specified namespace. This operation cannot be undone, so use with caution for critical data.
Parameters
- namespace: string
  Namespace containing the key to delete
- key: string
  Specific key to remove from storage
Returns Promise<void>
Throws
When deletion request fails or service is unavailable

Example: Delete User Preference
```
await deleteKeyValue('user-preferences', 'theme-mode');
console.log('Theme preference cleared');
```