fix: prevent panel unmount on extended tab inactivity

[fx]

Summary

• Enhanced the liebe-panel lifecycle management to prevent unmounting when tabs are inactive for extended periods
• Added comprehensive logging to track panel lifecycle events
• Implemented keep-alive mechanism that periodically touches the DOM and re-renders when needed
• Added MutationObserver to detect and prevent removal from parent
• Made panel initialization more robust to handle re-attachment scenarios

Problem

The liebe-panel was still being unmounted/removed by Home Assistant when the tab was inactive for extended periods (e.g., when the tab is not visible for a while). This was despite the previous fix in PR #132.

Solution

1. Keep-Alive Mechanism: Added a periodic check (every 30 seconds) that:

   • Touches DOM properties to keep the element "active"
   • Re-renders the React app if the page has been inactive for more than 5 minutes
   • Updates interaction timestamps when the page becomes visible again

2. MutationObserver: Implemented a parent observer that:

   • Detects when the panel is being removed from its parent
   • Attempts to re-add the panel if it has a valid hass object

3. Enhanced Initialization:

   • Better detection of when re-initialization is needed
   • Checks for lost shadow root or React root
   • Prevents panel from being garbage collected by storing reference on window

4. Comprehensive Logging: Added detailed logging throughout the lifecycle to help debug any future issues

Testing

• Built the panel successfully with npm run build:ha
• All TypeScript checks pass
• All linting checks pass
• All tests pass (463 tests)
• Added extensive logging to monitor behavior in production

Related Issue

This addresses the ongoing issue where the panel disappears after extended periods of tab inactivity.

Previous Attempt

PR #132 addressed tab switching but didn't fully resolve the issue for extended inactive periods.