Task 6: Map Loading States & Shared Error Toast Utility

[Vamshi-Gollapelly]

This PR implements Task 6 for the HMI map page.

Changes made:

• Added a reusable shared toast notification utility in HMI-utils.js
• Added a loading spinner overlay for the map while data is loading
• Added an error banner with a retry button when map data fails to load
• Added API timeout handling in routes.js so requests fail clearly instead of hanging
• Improved map page behaviour so it no longer goes blank on load failure

Files updated:

• src/Components/HMI/ui/public/index.html
• src/Components/HMI/ui/public/js/HMI-utils.js
• src/Components/HMI/ui/public/js/HMI.js
• src/Components/HMI/ui/public/js/routes.js

How to test:

1. Open the HMI page
2. Confirm the spinner appears while the map is loading
3. Confirm the toast utility shows notifications correctly
4. Simulate API/backend failure and confirm the error banner appears
5. Click Retry and confirm the app attempts to load again
6. Confirm requests timeout instead of hanging indefinitely

Outcome:
This update adds consistent user feedback for loading and failure states and provides a reusable toast utility for other team members to use.

[Vamshi-Gollapelly]

Hi, I’ve completed Task 6 (Map Loading States & Toast Utility).
Could you please review and let me know if any changes are needed?

[mraula]

everything looks good