[AlexAndBear]

Description

When saving a notification preference fails, the checkbox now goes back to its saved state instead of staying toggled, so the Preferences page no longer shows a setting that wasn't saved. This also covers the "Receive notification mails" checkbox and quick double clicks.

Related Issue

• Fixes Notification preference checkbox stays toggled when saving fails #4233

How Has This Been Tested?

• test environment: unit tests (Vitest), browser tests (Playwright) against a local OpenCloud
• test case 1: unit: failed saves restore the notification and mail checkboxes, double clicks end in the saved state, a newer click keeps its value while its save is pending
• test case 2: browser: failed and aborted saves revert In-App, Mail and "Receive notification mails" checkboxes (desktop and Pixel 7), pending state and double clicks, successful saves persist, keyboard toggling keeps focus

Types of changes

• Bugfix
• Enhancement (a change that doesn't break existing code or deployments)
• Breaking change (a modification that affects current functionality)
• Technical debt (addressing code that needs refactoring or improvements)
• Tests (adding or improving tests)
• Documentation (updates or additions to documentation)
• Maintenance (like dependency updates or tooling adjustments)