feat(delegate-task): add resolveMetadataModel helper for model fallback

Add helper that picks primary model with fallback to a secondary model

(e.g., categoryModel → parentContext.model). Enforces consistent

{providerID, modelID} shape.

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/tools/delegate-task/resolve-metadata-model.ts

@@ -0,0 +1,21 @@
+import type { DelegatedModelConfig } from "./types"
+
+export interface MetadataModel {
+  providerID: string
+  modelID: string
+}
+
+type ModelLike = Pick<DelegatedModelConfig, "providerID" | "modelID"> | MetadataModel
+
+export function resolveMetadataModel(
+  primary: ModelLike | undefined,
+  fallback: ModelLike | undefined,
+): MetadataModel | undefined {
+  if (primary) {
+    return { providerID: primary.providerID, modelID: primary.modelID }
+  }
+  if (fallback) {
+    return { providerID: fallback.providerID, modelID: fallback.modelID }
+  }
+  return undefined
+}