feat: unify installation model catalog

backend/src/pi/list-models.ts

@@ -18,6 +18,8 @@ export interface PiModel {
   reasoning: boolean;
 }
 
+export type ListModelsFn = () => Promise<PiModel[]>;
+
 interface Opts {
   spawnFn?: (
     command: string,
@@ -36,7 +38,7 @@ interface Opts {
  * configured) via an ephemeral `pi --mode rpc` process. Result is cached for
  * `ttlMs`. The returned function rejects on timeout/error; callers degrade.
  */
-export function createPiModelLister(cfg: AppConfig, opts: Opts = {}): () => Promise<PiModel[]> {
+export function createPiModelLister(cfg: AppConfig, opts: Opts = {}): ListModelsFn {
   const ttlMs = opts.ttlMs ?? 60_000;
   const now = opts.nowMs ?? (() => Date.now());
   const spawnFn = opts.spawnFn ?? nodeSpawn;