fix(agent): hide unrelated models for alias fallback

src/lib/llm/models.ts

@@ -75,14 +75,19 @@ export async function listLlmModels(options?: {
     }
 
     const models = normalizeLlmModelsPayload(await response.json());
-    const merged = new Map<string, LlmModelOption>();
-    merged.set(fallbackModel, fallbackOption);
-    for (const model of models) merged.set(model.id, model);
+
+    if (models.length === 0) {
+      return { models: [fallbackOption], fallbackModel, degraded: true };
+    }
+
+    if (!models.some((model) => model.id === fallbackModel)) {
+      return { models: [fallbackOption], fallbackModel, degraded: false };
+    }
 
     return {
-      models: [...merged.values()].sort((a, b) => a.id.localeCompare(b.id)),
+      models,
       fallbackModel,
-      degraded: models.length === 0,
+      degraded: false,
     };
   } catch {
     return { models: [fallbackOption], fallbackModel, degraded: true };

tests/unit/llm-models.test.ts

@@ -57,13 +57,13 @@ describe("isValidLlmModelId", () => {
 });
 
 describe("listLlmModels", () => {
-  it("fetches provider models with API key auth and includes the fallback model", async () => {
+  it("fetches provider models with API key auth when the fallback is advertised", async () => {
     const requests: Request[] = [];
     const result = await listLlmModels({
       config: openAiConfig,
       fetchImpl: async (input, init) => {
         requests.push(new Request(input, init));
-        return Response.json({ data: [{ id: "qwen2.5-coder" }] });
+        return Response.json({ data: [{ id: "qwen2.5-coder" }, { id: "llama3.2" }] });
       },
     });
 
@@ -88,6 +88,20 @@ describe("listLlmModels", () => {
     assert.equal(result.degraded, true);
   });
 
+  it("uses an unadvertised fallback alias instead of unrelated provider models", async () => {
+    const result = await listLlmModels({
+      config: { ...openAiConfig, model: "uncensored" },
+      fetchImpl: async () =>
+        Response.json({
+          data: [{ id: "auto" }, { id: "qwen3:8b" }, { id: "qwen3-coder:30b" }],
+        }),
+    });
+
+    assert.deepEqual(result.models, [{ id: "uncensored", label: "uncensored" }]);
+    assert.equal(result.fallbackModel, "uncensored");
+    assert.equal(result.degraded, false);
+  });
+
   it("uses fallback only for mock provider config", async () => {
     const result = await listLlmModels({
       config: { provider: "mock", baseUrl: null, apiKey: null, model: "llama3.2" },