Embedding adapter backed by Bumblebee's Nx.Serving.
Expects a pre-built serving (struct or registered process name) passed
via the :serving option. The serving must implement the text embedding
interface (e.g. created via Bumblebee.Text.text_embedding/3).
Options
:serving- (required) anNx.Servingstruct or registered process name:model- (optional) model name string for observability