feat: remove GPU support and simplify to CPU-only architecture

app/services/realesrgan_bridge.py

@@ -83,7 +83,7 @@ class RealESRGANBridge:
                 tile=settings.tile_size,
                 tile_pad=settings.tile_pad,
                 pre_pad=0,
-                half=('cuda' in settings.get_execution_providers()),
+                half=False,
             )
             
             self.current_model = model_name
@@ -134,7 +134,7 @@ class RealESRGANBridge:
                 tile=settings.tile_size,
                 tile_pad=settings.tile_pad,
                 pre_pad=0,
-                half=('cuda' in settings.get_execution_providers()),
+                half=False,
             )
             
             self.current_model = model_name
@@ -198,15 +198,6 @@ class RealESRGANBridge:
             return self.upsampler.scale
         return 4
 
-    def clear_memory(self) -> None:
-        """Clear GPU memory if available."""
-        try:
-            import torch
-            torch.cuda.empty_cache()
-            logger.debug('GPU memory cleared')
-        except Exception:
-            pass
-
 
 # Global instance
 _bridge: Optional[RealESRGANBridge] = None