fix(backend): deterministic /models fallback test + merge duplicate import

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/test/routes-sql-meta.test.ts

@@ -148,15 +148,14 @@ test("GET /models returns {models:[]} when listModels throws (graceful fallback)
   expect(res.json()).toEqual({ models: [] });
 });
 
-test("GET /models with no listModels injected uses real lister (returns array)", async () => {
-  // No listModels dep → createPiModelLister (real); returns PiModel[] (possibly empty if Pi not running)
+test("GET /models with empty listModels stub returns empty array", async () => {
   const app = buildApp(loadConfig({ THT_HARNESS_DIR: "../harness" }), {
     thtRunner: {} as any,
-    // listModels intentionally omitted
+    listModels: async () => [],
   });
 
   const res = await app.inject({ method: "GET", url: "/models" });
 
   expect(res.statusCode).toBe(200);
-  expect(Array.isArray(res.json().models)).toBe(true);
+  expect(res.json()).toEqual({ models: [] });
 });