A gguf model's assigned/loaded key is its file path, but /v1/models
advertises it — and clients address it — by the filename without the
.gguf suffix (the automatic alias). engine_for_assigned /
engine_for_model / _key_matches_path compared short names verbatim, so
the automatic alias never matched the .gguf key and routing fell through
(404 / wrong engine). Normalize both sides via _short_stem so the
automatic alias resolves to the owning engine with no manual alias.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>