Refactor to unify scripts/categories as Executable

This commit consolidates scripts and categories under a unified
'Executable' concept. This simplifies the architecture and improves code
readability.

- Introduce subfolders within `src/domain` to segregate domain elements.
- Update class and interface names by removing the 'I' prefix in
  alignment with new coding standards.
- Replace 'Node' with 'Executable' to clarify usage; reserve 'Node'
  exclusively for the UI's tree component.

src/application/Context/State/Selection/Script/UserSelectedScript.ts

@@ -1,12 +1,12 @@
 import { BaseEntity } from '@/infrastructure/Entity/BaseEntity';
-import type { IScript } from '@/domain/IScript';
+import type { Script } from '@/domain/Executables/Script/Script';
 import type { SelectedScript } from './SelectedScript';
 
 type SelectedScriptId = SelectedScript['id'];
 
 export class UserSelectedScript extends BaseEntity<SelectedScriptId> {
   constructor(
-    public readonly script: IScript,
+    public readonly script: Script,
     public readonly revert: boolean,
   ) {
     super(script.id);