fix: clean up disk file when setFilePath fails in receiveServerFile

When setFilePath fails (file deleted or blocked concurrently, or
duplicate upload), the uploaded file was left orphaned on disk with
no DB record pointing to it. Now the file is removed on failure,
matching the cleanup in the receiveChunk error path.

src/Simplex/FileTransfer/Server.hs

@@ -570,6 +570,7 @@ processXFTPRequest HTTP2Body {bodyPart} = \case
                   Left _e -> do
                     us <- asks usedStorage
                     atomically $ modifyTVar' us $ subtract (fromIntegral size)
+                    liftIO $ whenM (doesFileExist fPath) (removeFile fPath) `catch` logFileError
                     pure $ FRErr AUTH
               Left e -> do
                 us <- asks usedStorage