Stop abstraction via the trait Notifier

[ubnt-intrepid]

• 冗長な抽象化なので元に戻す

[Copilot]

Pull request overview

This PR removes the Notifier trait abstraction and consolidates the notification functionality directly into the Notifier<'sess, T> struct implementation. The PR description indicates this was done to eliminate redundant abstraction ("冗長な抽象化なので元に戻す" - "Reverting redundant abstraction").

Key changes:

• Deleted the notify.rs module and moved all notification methods to session.rs
• Converted trait methods to inherent methods on the Notifier<'sess, T> struct
• Removed trait imports from example files (no longer needed with inherent methods)

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/notify.rs	Complete removal of the Notifier trait and its default implementations
src/session.rs	Added all notification methods as public inherent methods on Notifier<'sess, T>; inlined new_notify_unique logic into retrieve method
src/lib.rs	Removed the notify module from public exports
examples/poll.rs	Removed notify::Notifier as _ trait import
examples/heartbeat_entry.rs	Removed notify::Notifier as _ trait import
examples/heartbeat.rs	Removed notify::Notifier as _ trait import