Update postergeist.py

Fix: Hide overlay when poster fills canvas

The overlay was previously being displayed on all images, including those that filled the entire vertical space of the canvas. This was not the intended behavior as it could obscure the poster.

This commit modifies the `prepare_image_frame` method to add a conditional check. The overlay is now only rendered if the poster's height is less than the canvas's height, ensuring it only appears when there is empty, letterboxed space at the bottom.

Author: pasiegel

postergeist.py

@@ -98,7 +98,7 @@ def prepare_image_frame(self, img_to_process):
         poster_y = 0
         background.paste(poster, (poster_x, poster_y))
 
-        if self.overlays:
+        if self.overlays and poster.height < canvas_h:
             overlay_path = random.choice(self.overlays)
             try:
                 with Image.open(overlay_path) as overlay_img: