Real-image posters: a new size is a new image id, never a changed placement

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

internal/ui/app.go

@@ -193,8 +193,8 @@ func New(cfg *config.Config) *App {
 }
 
 // noteWindow notices when the terminal's size or cell size changed. The
-// placements of real-image posters are then made again: the picture would
-// otherwise rely on the terminal rescaling an existing placement correctly.
+// real-image posters are then uploaded and placed again from scratch instead of
+// relying on the terminal to rescale what is there.
 func (a *App) noteWindow(s tcell.Screen) {
 	w, h := s.Size()
 	win := [3]int{w, h, int(a.cellAspect * 1000)}
@@ -204,7 +204,7 @@ func (a *App) noteWindow(s tcell.Screen) {
 	first := a.lastWindow == [3]int{}
 	a.lastWindow = win
 	if !first && a.gfx != nil {
-		a.gfx.invalidate()
+		a.gfx.deleteAll()
 	}
 }