feat(zai): auto-detect endpoint + default glm-5 (#14786)

* feat(zai): auto-detect endpoint + default glm-5

* test: fix Z.AI default endpoint expectation (#14786)

* test: bump embedded runner beforeAll timeout

* chore: update changelog for Z.AI GLM-5 autodetect (#14786)

* chore: resolve changelog merge conflict with main (#14786)

* chore: append changelog note for #14786 without merge conflict

* chore: sync changelog with main to resolve merge conflict

src/agents/pi-embedded-runner/model.test.ts

@@ -242,6 +242,41 @@ describe("resolveModel", () => {
     });
   });
 
+  it("builds a zai forward-compat fallback for glm-5", () => {
+    const templateModel = {
+      id: "glm-4.7",
+      name: "GLM-4.7",
+      provider: "zai",
+      api: "openai-completions",
+      baseUrl: "https://api.z.ai/api/paas/v4",
+      reasoning: true,
+      input: ["text"] as const,
+      cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+      contextWindow: 200000,
+      maxTokens: 131072,
+    };
+
+    vi.mocked(discoverModels).mockReturnValue({
+      find: vi.fn((provider: string, modelId: string) => {
+        if (provider === "zai" && modelId === "glm-4.7") {
+          return templateModel;
+        }
+        return null;
+      }),
+    } as unknown as ReturnType<typeof discoverModels>);
+
+    const result = resolveModel("zai", "glm-5", "/tmp/agent");
+
+    expect(result.error).toBeUndefined();
+    expect(result.model).toMatchObject({
+      provider: "zai",
+      id: "glm-5",
+      api: "openai-completions",
+      baseUrl: "https://api.z.ai/api/paas/v4",
+      reasoning: true,
+    });
+  });
+
   it("keeps unknown-model errors for non-gpt-5 openai-codex ids", () => {
     const result = resolveModel("openai-codex", "gpt-4.1-mini", "/tmp/agent");
     expect(result.model).toBeUndefined();