fix

backend/src/services/documents.rs

@@ -1420,12 +1420,32 @@ impl<'a> DocumentsService<'a> {
                 checksum = %checksum_hex,
                 "upload rejected because document already exists",
             );
+
+            let mut message = String::from("a document with the same contents already exists");
+            let mut details = json!({
+                "conflict_document_id": document.id,
+            });
+
+            if let Some(deleted_at) = document.deleted_at {
+                message.push_str(
+                    ". Note: the existing document is currently in the trash.",
+                );
+                if let Some(obj) = details.as_object_mut() {
+                    obj.insert(
+                        "conflict_document_in_trash".to_string(),
+                        Value::Bool(true),
+                    );
+                    obj.insert(
+                        "conflict_document_deleted_at".to_string(),
+                        Value::String(to_iso(deleted_at)),
+                    );
+                }
+            }
+
             return Err(
-                AppError::conflict("a document with the same contents already exists")
+                AppError::conflict(message)
                     .with_code("duplicate_document")
-                    .with_details(json!({
-                        "conflict_document_id": document.id,
-                    })),
+                    .with_details(details),
             );
         }