scripts/mlx_image_server.py resolved the model per request
(`req.model or _args.model`) on both /v1/images/generations and
/v1/images/edits, so the caller chose which model was served.
`_is_hidream()` is a substring test and `_snapshot_path()` accepts either a
local directory or a Hugging Face repo id, so a caller-supplied string
selected the HiDream branch and then supplied the directory it runs
`scripts/hidream_o1/generate_hidream_o1_mlx.py` from, under sys.executable.
The server has no auth, and the Cookbook binds it to 0.0.0.0 whenever it is
serving to a remote host, so one POST executed attacker code on the serving
host.
Both paths now use `_args.model`. The request field is still accepted for
OpenAI wire compatibility and ignored, matching scripts/diffusion_server.py,
and Odysseus already sends the served model's own id, so this is a no-op for
legitimate callers. /v1/images/harmonize already pinned.
Regression tests cover both endpoints, the local-directory and
Hugging-Face-repo halves, and that a server actually launched with a HiDream
model still serves it. Three of the four fail on the unfixed code.
