fix(coding-agent): prefer newer generated model catalogs

packages/ai/src/models-store.ts

@@ -2,6 +2,8 @@ import type { Api, Model } from "./types.ts";
 
 export interface ModelsStoreEntry {
 	models: readonly Model<Api>[];
+	/** Unix timestamp from the remote catalog's Last-Modified header. */
+	lastModified?: number;
 	/** Unix timestamp of the last completed remote check. */
 	checkedAt?: number;
 }

packages/ai/src/providers/all.ts

@@ -67,6 +67,11 @@ export function getBuiltinProviders(): BuiltinProvider[] {
 	return Object.keys(MODELS) as BuiltinProvider[];
 }
 
+/** URL of a generated provider catalog, used to compare its mtime with remote catalogs during development. */
+export function getBuiltinModelDataUrl(provider: BuiltinProvider): URL {
+	return new URL(`./data/${provider}.json`, import.meta.url);
+}
+
 export function getBuiltinModels<TProvider extends BuiltinProvider>(
 	provider: TProvider,
 ): Model<BuiltinModelApi<TProvider, keyof (typeof MODELS)[TProvider]>>[] {