fix: prevent memory leak by cancelling all timers in onClose

[vibhutomer]

Description

This PR addresses a memory leak in the HomeController where background timers were not being properly disposed of when the controller was closed.

Proposed Changes

• Modified the onClose() method in lib/app/modules/home/controllers/home_controller.dart.
• Added explicit .cancel() calls for the periodic _timer and the nullable _delayTimer.
• This ensures that background processes are halted when the user navigates away from the Home screen, saving battery and preventing potential null-pointer exceptions during UI updates.

Fixes #884

Screenshots

N/A - This is a background performance fix. No visible UI changes, but it improves memory management and battery efficiency.

Checklist

• Tests have been added or updated to cover the changes
• Documentation has been updated to reflect the changes
• Code follows the established coding style guidelines
• All tests are passing