Fork the VST3 class UID (beta UID minted+frozen), on-disk name, and display
name by the one channel bit via app_version; couple UID selection to the
channel at compile time so a refactor can't split identity from data.
Extension stamps a monotonic bank_generation counter, bumped at content
mutations; the VST3 instrument polls it off-thread on an editor timer and
consumes assignment requests, refreshing playback hands-free.
Inline keymap/level strip drawn into REAPER's embed bitmap, reusing the LICE
idiom. Pure embed_strip layout/hit-test (tested); processor exposes the embed
interface off queryInterface and publishes an RT-safe block peak for the level.
daniel