Add new assets and implement theme settings

- Added a new pointer image to the assets directory.
- Created dark and light stylesheet files for UI theming.
- Implemented a settings dialog with placeholder text.
- Defined a Theme enumeration to manage different UI themes.
-  and more

.github/ISSUE_TEMPLATE/config.yml

@@ -1,3 +1,3 @@
-blank_issues_enabled: true
+blank_issues_enabled: false
 1-bug.yml 
 2-feature-request.yml

.github/workflows/nightly.yml

@@ -25,7 +25,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
-          python-version: "3.x"
+          python-version: "3.12.x"
 
       - name: Install dependencies
         run: |