refactor: improve cloud-init script UX and remove description field

Changes:
1. Remove description field from cloud-init scripts
   - Updated migration to remove description column
   - Updated model to remove description from fillable array

2. Redesign script name input layout
   - Move script name input next to checkbox (always visible)
   - Remove conditional rendering - input always shown
   - Use placeholder instead of label for cleaner look

3. Fix dropdown type error
   - Replace wire:change event with wire:model.live
   - Use updatedSelectedCloudInitScriptId() lifecycle hook
   - Add "disabled" attribute to placeholder option
   - Properly handle empty string vs null in type casting

4. Improve validation
   - Require both script content AND name for saving
   - Remove description validation rule
   - Add selected_cloud_init_script_id validation

5. Auto-populate name when loading saved script
   - When user selects saved script, auto-fill the name field

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/Models/CloudInitScript.php

@@ -10,7 +10,6 @@ class CloudInitScript extends Model
         'team_id',
         'name',
         'script',
-        'description',
     ];
 
     protected function casts(): array