- LOAD job posts WM_CLOSE to window created on main thread (DestroyWindow from worker crashed 0xc000041d, muting all tracks)
- handleOpenGui + attach jobs skip when Vst3Instrument::hasAttachedView() (state_ && guiAttached_)
- attach failure posts WM_CLOSE; post_close_gui erases entry only when it points at the same hwnd
- cap openVstGuiRetry at 5 to stop frontend retry spam
- Close other channels' editor windows before attaching a new one (Option B)
- needsReload()/setReloading() guard: skip processAudioBlock during
terminate+reload teardown to avoid UAF/hang when reopening GUI
- Wait for editor registry cleanup (5s timeout) before creating window