docs: threat-model: move fake devices out of "non production use"

docs: threat-model: move fake devices out of "non production use"

When originally writing the "fake USB device" entry, it was difficult
to find a suitable section for it and it ended up in "non production
use" but that doesn't fit particularly well. Actually it's very similar
to crafted filesystems, it's a matter of spec violation. Both drivers
and FS are written against a spec, and what the threat model doesn't
cover is out-of-spec use. So let's move the entry there and rename the
crafted FS entry to "Non-conforming devices and media" instead.

Overall it looks more consistent.

The spec was tested agains Qwen3.6-27B-Architect-Polaris2-Fable-B-F451,
Opus-5 and Gemini by reading the threat-model file, then reading a tens
of FS and driver fixes, and they were now all properly classified as
regular bugs, except two that Gemini and Opus rightfully classified as
vulns (Qwen didn't spot the security potential but that's out of our
scope).

Cc: Greg KH <greg@kroah.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Link: https://patch.msgid.link/20260802203540.3453-3-w@1wt.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>