Function selectModel

selectModel(
graph: MeshGraph,
options: ModelSelectOptions,
): Promise<SelectedModel | null>
Select the best model for an agent capability, with budget-aware downgrade.

Queries the mesh RDF graph via the model-select-budget-aware SPARQL template. If the token budget ratio falls below budgetThreshold, the cheapest available model is returned instead of the highest-quality one.

Returns null if no agents with the requested capability and linked model capabilities are found in the graph.
Parameters
- graph: MeshGraph
  The MeshGraph to query.
- options: ModelSelectOptions
  Model selection options.
Returns Promise<SelectedModel | null>
The selected SelectedModel, or null if none found.
Example
```
const model = await selectModel(graph, {
  capabilityIri: 'https://meshpocalypse.dev/ontology#Summarise',
  budgetIri: 'https://meshpocalypse.dev/budget/tenant-a',
  budgetThreshold: 0.2,
});
if (model) {
  console.log(model.downgraded ? 'Using cheap model:' : 'Using quality model:', model.modelId);
}
```
- Defined in packages/core/src/core/routing/model-selector.ts:189