Re applied all the notification fixes indivividually

[Mudit200408]

Verify Duplicate Card Prevention:

1. Send a notification from Android (e.g., ID 123).
2. Send the exact same notification again. Confirm no duplicate card is added and no new
   sound/banner triggers.
3. Send an updated version (same ID 123, modified text). Confirm the card updates in-place
   and triggers a native alert.
   For example, if a background process or music player keeps sending the exact same notification state (same ID, same title, same body) to the Mac repeatedly, the Mac app will now update the existing card in place instead of piling up identical duplicate cards in your list, and it won't keep playing alert sounds for unchanged content.

Verify Focus Mode / DND Sync Behavior:

1. Turn on Do Not Disturb or disable notifications for the app in macOS System Settings.
2. Send a notification.
3. Confirm that notifications persist in the Mac Ul and are not incorrectly auto-deleted by the
   sync process.

Verify Local Dismissal (Hide):

1. Click Hide on a notification card in the Mac app.
2. Confirm the card is dismissed only on Mac and remains active on Android.
   Build Integrity:
3. Clean and build the Xcode project. Confirm build succeeds.

[sameerasw]

Thank you!