## 1. Notification API Migration

- [x] 1.1 Add the documented `BoundNotificationService`, `AddressedNotificationService`, and `NotificationDestination` API under `com.r35157.service.notification`.
- [x] 1.2 Remove the old API package, marker interface, notifier contracts, and all compatibility aliases.

## 2. Transport Implementations

- [x] 2.1 Migrate and rename Pushover to `PushoverNotificationService`, accept and validate `ΩNotificationMessageΩ`, and preserve the existing delivery flow.
- [x] 2.2 Migrate and rename Discord to `DiscordNotificationService`, validate direct messages, and preserve its unimplemented delivery status.
- [x] 2.3 Migrate SMTP to `SMTPNotificationService` with a validated address-and-subject `SMTPDestination`, direct binding convenience, direct message validation, and unimplemented delivery status.
- [x] 2.4 Update every production call site and inline example, then confirm the old package and removed types have no remaining production references.

## 3. Verification

- [x] 3.1 Compile main and test source sets and complete the repository's normal assembly/build without changing tests.
- [x] 3.2 Strictly validate the OpenSpec change and run whitespace/diff checks.
- [x] 3.3 Review the complete diff for scope, generated-source changes, test changes, transport-independent consumer dependencies, and preservation of excluded services.