fix: Apply modern Black formatting and fix flake8 line length

src/document_management/upload_service.py

@@ -101,13 +101,14 @@ class UploadService:
                 results["message"] = "All uploads failed"
             else:
                 results["status"] = "partial"
-                results[
-                    "message"
-                ] = f"{results['successful_uploads']} files uploaded, {results['failed_uploads']} failed"
+                results["message"] = (
+                    f"{results['successful_uploads']} files uploaded, "
+                    f"{results['failed_uploads']} failed"
+                )
         else:
-            results[
-                "message"
-            ] = f"Successfully uploaded {results['successful_uploads']} files"
+            results["message"] = (
+                f"Successfully uploaded {results['successful_uploads']} files"
+            )
 
         return results