Inability to upload specific files

### Describe the bug

While synchronizing my old family dives I noticed that some of the files broke the uploads. Throughout the whole drive there were around 2 of them, so it is not common, but unfortunately it made me restart an upload of ~200K files a couple of times.

Generally what happens is that the file is stuck at "hashing" and it stalls the upload.

### To Reproduce
1. Try to upload an affected file (I attached the one, which causes the bug for me)

### Expected behavior
The file should just be uploaded.

### Screenshots

The network tab and the message:

The upload queue:

### Server details
* **server OS / version:** Nix OS 25.05
* **what copyparty did you grab:** (sfx/exe/pip/arch/...) sfx
* **how you're running it:** (in a terminal, as a systemd-service, ...) Systemd service
* run copyparty with `--version` and grab the last 3 lines (they start with `copyparty`, `CPython`, `sqlite`) and paste them below this line:
(a bit of a cheat since in Nix Os services have their own environment, but still)
copyparty v1.18.6 "logtail" (2025-07-28)
CPython v3.12.11 on Linux64 [GCC 14.2.1 20250322]
sqlite 3.48.0*1 | jinja 2.11.3 | pyftpd 1.5.10 | tftp 0.4.0

* **copyparty arguments and/or config-file:** z, zsv, dedup, reflink, e2dsa, e2ts

### Client details
if the issue is possibly on the client-side, then mention some of the following:
* the device type and model: custom PC
* OS version: Windows 11
* browser version: Brave 1.80.125

### Additional context
The file in question (zipped because github) (I have no idea what is it, so do not execute): [fpcount.zip](https://github.com/user-attachments/files/21586090/fpcount.zip)