What is this PR for?

In the Simple look-and-feel mode, notebook controls in the action bar and navigation buttons in the sidebar are hidden by default and rely on :hover interactions to be revealed.

On touch-only devices without a hover-capable pointer, users are unable to trigger hover states, rendering these essential notebook-level actions inaccessible.

This PR adds @media (any-hover: none) style fallbacks for both the action-bar and sidebar components in Simple mode, ensuring that essential controls and navigation items remain visible and accessible on touch-only devices while preserving the existing hover-to-reveal behavior on desktop environments.

What type of PR is it?

[Bug Fix]

Todos

• Add @media (any-hover: none) fallback styles for .control (display: block) and .setting (display: flex) in action-bar.component.less.
• Add @media (any-hover: none) fallback styles for .sidebar-button and .sidebar-nav (opacity: 1) in sidebar.component.less.
• Add Playwright E2E spec (simple-look-and-feel-input.spec.ts) for verifying touch-only / non-hover interactions.
• Retain existing hover-to-reveal behavior on hover-capable desktop environments.

What is the Jira issue?

• Open issue: ZEPPELIN-6587
• PR Link: [ZEPPELIN-6587] Keep simple notebook controls accessible without hover #5537

How should this be tested?

1. Playwright E2E Test:
   • Run the newly added Playwright test spec:

     cd zeppelin-web-angular && npx playwright test e2e/tests/notebook/simple-look-and-feel/simple-look-and-feel-input.spec.ts

2. Touch Device Emulation (Chrome DevTools):
   • Open Developer Tools -> Toggle Device Toolbar (or emulate (any-hover: none)).
   • Open a notebook in Simple mode.
   • Verify that action-bar controls, note settings, and sidebar buttons remain accessible.
3. Desktop Verification:
   • Verify in a normal desktop browser that controls in Simple mode remain hidden by default and appear on mouse hover.
4. Linting:
   • Run cd zeppelin-web-angular && npm run lint.

Screenshots (if appropriate)

(Optional: Attach screenshots of Simple mode in an emulated touch context)

Questions:

• Does the licenses files need to update? No
• Is there breaking changes for older versions? No
• Does this need user documentation changes? No