allow proxy auto model selection

src/test/main.test.js

@@ -131,6 +131,12 @@ describe('main pipeline', () => {
     assert.equal(await runMain(), 0);
   });
 
+  it('無 MODEL 仍可由 Proxy 自動選模並正常走完（exit 0）', async () => {
+    assert.equal(await runMain({
+      config: { getLLMConfig: () => ({ provider: 'cliproxyapi', apiKeys: ['secret'], baseURL: 'https://proxy.example', model: null, command: null }) },
+    }), 0);
+  });
+
   it('clone 失敗仍繼續、不因 commitAndPush 中斷（無 critical → exit 0）', async () => {
     assert.equal(await runMain({ git: { cloneRepo: () => { throw new Error('clone fail'); } } }), 0);
   });