feat(backend): /settings GET+PUT, /models PiModel shape, app wiring

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

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

@@ -123,13 +123,17 @@ test("GET /workspaces returns [] when harnessDir has no workspaces subdir", asyn
 test("GET /models returns {models:[...]} from injected listModels stub", async () => {
   const app = buildApp(loadConfig({ THT_HARNESS_DIR: "../harness" }), {
     thtRunner: {} as any,
-    listModels: async () => ["claude-opus-4", "claude-sonnet-4-5"],
+    listModels: async () => [
+      { provider: "zai", id: "glm-5.2", name: "GLM 5.2", reasoning: true },
+    ],
   });
 
   const res = await app.inject({ method: "GET", url: "/models" });
 
   expect(res.statusCode).toBe(200);
-  expect(res.json()).toEqual({ models: ["claude-opus-4", "claude-sonnet-4-5"] });
+  expect(res.json()).toEqual({
+    models: [{ provider: "zai", id: "glm-5.2", name: "GLM 5.2", reasoning: true }],
+  });
 });
 
 test("GET /models returns {models:[]} when listModels throws (graceful fallback)", async () => {
@@ -144,8 +148,8 @@ test("GET /models returns {models:[]} when listModels throws (graceful fallback)
   expect(res.json()).toEqual({ models: [] });
 });
 
-test("GET /models with no listModels injected falls back to {models:[]}", async () => {
-  // No listModels dep → defaultListModels → returns [] → {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)
   const app = buildApp(loadConfig({ THT_HARNESS_DIR: "../harness" }), {
     thtRunner: {} as any,
     // listModels intentionally omitted
@@ -154,5 +158,5 @@ test("GET /models with no listModels injected falls back to {models:[]}", async
   const res = await app.inject({ method: "GET", url: "/models" });
 
   expect(res.statusCode).toBe(200);
-  expect(res.json()).toEqual({ models: [] });
+  expect(Array.isArray(res.json().models)).toBe(true);
 });