185 new tab format (#294)

![image](https://github.com/user-attachments/assets/458db80c-4e24-49ad-b9c1-b34203d1c6d0)
- [x] style colors
- [x] style button shapes
- [x] style selected / unselected 
- [x] add opacity / transparency variation to selected tab. 
- [x] reduce height of button slightly.
- [x] align arrows
- [x] Improve tab separator containment within tab control
- [x] ensure scroll=auto in both modes

.github/workflows/npm.yaml

@@ -17,3 +17,4 @@ jobs:
       - run: npm ci
       - run: npm run build
       - run: npm run typecheck
+      - run: npm run stylelint

.vscode/extensions.json

@@ -0,0 +1,3 @@
+{
+  "recommendations": ["stylelint.vscode-stylelint"]
+}