RomM version
4.0.1

Describe the bug
When manually uploading a manual, the .pdf file is saved to the wrong location, which means it is not detected as the rom manual.

The .pdf file can be found in the library/ folder in the docker container (e.g. /romm/library/roms/5/960/manual/960.pdf`) and no manual/ subfolder or .pdf file exists under resources/.

To Reproduce

1. Open any rom without a manual
2. Edit it, and upload the pdf file
3. Apply the changes
4. Even after reloading, the manual does not show up

Expected behavior
The manual should be shown in the rom page after upload.

Relevant logs

�[32mINFO�[39m:	  �[34m[RomM]�[95m[rom]�[36m[2025-08-12 18:12:34] �[0mUploading manual to �[33m/romm/library/roms/5/3378/manual/3378.pdf�[0m
�[32mINFO�[39m:	  �[34m[RomM]�[95m[httptools_impl]�[36m[2025-08-12 18:12:34] �[0m192.168.1.1:0 - "POST /api/roms/3378/manuals HTTP/1.0" 200
INFO:     [RomM][nginx][2025-08-12 18:12:34] 192.168.1.1 | - | POST /api/roms/3378/manuals 200 | 0 | Firefox Windows | 0.403```