Refactor: remove AGPL imgly dependency and migrate background removal to python backend

src/utils/mediaDimensions.ts

@@ -0,0 +1,32 @@
+export async function detectMediaDimensionsAndAspect(
+  url: string,
+  type: 'video' | 'image'
+): Promise<{ width: number; height: number; format: 'video' | 'image'; aspect: string }> {
+  return new Promise((resolve, reject) => {
+    if (type === 'image') {
+      const img = new Image();
+      img.onload = () => {
+        resolve({
+          width: img.width,
+          height: img.height,
+          format: 'image',
+          aspect: `${img.width}:${img.height}`,
+        });
+      };
+      img.onerror = () => reject(new Error('Failed to load image to detect dimensions.'));
+      img.src = url;
+    } else {
+      const video = document.createElement('video');
+      video.onloadedmetadata = () => {
+        resolve({
+          width: video.videoWidth,
+          height: video.videoHeight,
+          format: 'video',
+          aspect: `${video.videoWidth}:${video.videoHeight}`,
+        });
+      };
+      video.onerror = () => reject(new Error('Failed to load video to detect dimensions.'));
+      video.src = url;
+    }
+  });
+}