Apple Notes integration

[robin-liquidium]

add apple notes integration to the notes feature so new notes are also saved in apple notes and apple notes also show up in menu sheet.

[robin-liquidium]

Not part of the upcoming 0.2.0 release — deferred to a later one. Apple Notes has no real API; the only integration path is AppleScript automation, which is flaky, needs extra automation permissions, and is a much bigger lift than the rest of the roadmap. Still planned, just not yet.