Fix: Unhandled push notification error on unsupported browsers

[sentry]

Description

This PR addresses the issue SABLE-MB, where an unhandled error "Push messaging is not supported in this browser." was thrown repeatedly on browsers lacking Push API support (e.g., DuckDuckGo, certain mobile browsers).

The fix implements the following changes:

1. Graceful enablePushNotifications: The enablePushNotifications function in PushNotifications.tsx now returns gracefully instead of throwing an error when serviceWorker or PushManager is unavailable. This prevents unhandled exceptions and improves application stability on unsupported platforms.
2. Capability Guard in togglePusher: The togglePusher function now includes an isPushSupported() check at its entry point. This prevents any attempts to enable or disable push notifications if the browser does not support the necessary APIs, stopping the error from occurring on visibility changes.
3. Conditional UI Rendering: The WebPushNotificationSetting component in SystemNotification.tsx now checks isPushSupported() and returns null if push notifications are not supported. This hides the push notification settings UI from users on incompatible browsers, preventing them from enabling a non-functional feature.
4. isPushSupported Helper: A new exported helper function isPushSupported was added to PushNotifications.tsx to centralize the browser capability check.

Fixes #SABLE-MB

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings

AI disclosure:

• Partially AI assisted (clarify which code was AI assisted and briefly explain what it does).
• Fully AI generated (explain what all the generated code does in moderate detail).

Fixes SABLE-MB

[github-actions]

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[github-actions]

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[7w1]

bad bot (i think i disabled this on the sentry site so it shouldn’t be making prs anymore)