What does it do?

This fix adds defensive checks to prevent runtime errors when the tours property is undefined or missing in the guided tour state. The changes add null/undefined guards in two components:

1. Step.tsx (DefaultActions component): Added a safety check that returns null if state.tours or the specific tour (state.tours[tourName]) is undefined before attempting to access currentStep.

2. Tours.tsx (GuidedTourTooltipImpl component): Added a safety check that renders children without the tooltip wrapper if state.tours or the specific tour is undefined, allowing the page to function normally without the guided tour.

Why is it needed?

This solves Issue #25287 where the application crashes with:

Cannot read properties of undefined (reading '[tourName]')

This error occurs when:

• The guided tour state is corrupted or not properly initialized
• The tours data structure is missing from the state
• Users have old/stale localStorage data
• State hydration fails during initial load

Without these checks, attempting to access state.tours[tourName].currentStep throws an error that breaks the entire admin interface. These defensive checks ensure graceful degradation - if the guided tour data is unavailable, the UI continues to work without the tour functionality.

How to test it?

Test Case 1 - Simulate corrupted state:

1. Open browser DevTools → Application → Local Storage
2. Find the key containing guided tour state
3. Manually corrupt it by removing the tours property or setting it to undefined
4. Refresh the admin panel
5. Expected: Page loads normally without errors (previously would crash)

Test Case 2 - Normal flow:

1. Clear browser cache and localStorage
2. Navigate to the admin panel
3. Interact with pages that trigger guided tours
4. Expected: Guided tours work normally when state is properly initialized

Verification Path:

1. Navigate to: /admin
2. Monitor browser console for errors related to state.tours
3. Verify the admin interface loads without crashes

Related issue(s)/PR(s)

Fixes #25287