Dank-Bar Widgets UI Guideline

### Feature Description

Widgets Should Follow Some Basic Guideline Like Not Have Close BTN **/** Icon, Items Should Have Animation, Having Some Basic Customization's.

### Use Case

Close Btn Looks Out Of Place & Better UI **/** UX.

### Compositor(s)

- [x] All compositors
- [x] Niri
- [ ] Hyprland
- [ ] MangoWC (dwl)
- [ ] Sway
- [ ] Other (specify below)

### Proposed Solution

_No response_

### Alternatives/Existing Solutions

_No response_

The issue names no files, tests, or entry points, and its proposed solution is empty. Before implementation, clarify the widget guideline, the checked compositor scope, and acceptance criteria for close-button treatment, animation, and customization.

Written by the indexing model from the issue text.