[Priveetee]

Prepare the push notification reliability update for Android 1.10.0-beta.4.

• Retry failed push registration and recover missed notifications locally.
• Classify incoming push messages and include delivery traces in diagnostics.
• Report posted, suppressed, or failed notifications so the server can retry unconfirmed deliveries.
• Remind users that push alerts require the channel bell to be enabled.

Validation:

• 866 unit tests passed, 0 failures, 1 skipped.
• Lint, debug and release builds passed.
• Server service/HTTP tests and OpenAPI validation passed.

The server endpoint must be deployed before end-to-end beta notification delivery can be verified.