fix(ai-review model validation): 驗證 model 並支援自動選模

src/test/preflight.test.js

@@ -208,6 +208,20 @@ describe('verifyLLM', () => {
     assert.match(result.error, /不在 CLIProxyAPI 可用清單/);
     assert.match(result.error, /gpt-9-imaginary/);
   });
+
+  it('fails when the configured model name is invalid', async () => {
+    clearLLMEnv();
+    process.env.CLI_PROXY_API = 'https://proxy.example';
+    process.env.MODEL = 'gpt-5.5; rm -rf /';
+
+    const result = await verifyLLM({
+      fetchLLMModelsFn: async () => ({ ok: true, slugs: ['gpt-5.5'] }),
+    });
+
+    assert.equal(result.ok, false);
+    assert.equal(result.provider, 'cliproxyapi');
+    assert.match(result.error, /無效的 model 參數/);
+  });
 });
 
 describe('runPreflight', () => {