fix: ACP NewSessionResponse 恢复返回 models 字段

67fdd4ca 那次合规审计误将 models 从响应里移除，但 SDK 0.19.2 的 schema 实际允许
models?: SessionModelState | null（标注 UNSTABLE 仅表示"未来可能变"，并非
"agent 禁止返回"）。标准 ACP 客户端（Cursor/Zed/VS Code/RCS）依赖此字段填充
模型选择器 —— 缺失会导致客户端 supportsModelSelection=false，模型切换 UI 不可用。

- createSessionMethod: return 里加回 models
- sessionLifecycle: getOrCreateSession 两处 return 透传 models（resume/load 路径）
- agent.test: 更新过时的 "models omitted for v1 compliance" 断言

Co-Authored-By: glm-5.2 <zai-org@claude-code-best.win>

src/services/acp/__tests__/agent.test.ts

@@ -325,13 +325,17 @@ describe('AcpAgent', () => {
       expect(res.sessionId.length).toBeGreaterThan(0)
     })
 
-    test('returns modes and configOptions (models omitted for v1 compliance)', async () => {
+    test('returns modes, configOptions, and models (clients need models to populate selector)', async () => {
       const agent = new AcpAgent(makeConn())
       const res = await agent.newSession({ cwd: '/tmp' } as any)
       expect(res.modes).toBeDefined()
       expect(res.configOptions).toBeDefined()
-      // Stable v1 NewSessionResponse does not define `models`
-      expect((res as any).models).toBeUndefined()
+      // SDK 0.19.2 marks NewSessionResponse.models as UNSTABLE but the schema allows it, and
+      // standard clients (Cursor/Zed/VS Code) read it to populate the model selector. Omitting
+      // it forces supportsModelSelection=false on the client.
+      expect(res.models).toBeDefined()
+      expect(Array.isArray(res.models!.availableModels)).toBe(true)
+      expect(typeof res.models!.currentModelId).toBe('string')
     })
 
     test('each call returns a unique sessionId', async () => {
@@ -865,8 +869,8 @@ describe('AcpAgent', () => {
       } as any)
       expect(agent.sessions.has(requestedId)).toBe(true)
       expect(res.modes).toBeDefined()
-      // models is omitted for v1 compliance
-      expect((res as any).models).toBeUndefined()
+      // resume also returns models so clients can render the selector after reconnect.
+      expect(res.models).toBeDefined()
     })
 
     test('reuses existing session when sessionId matches and fingerprint unchanged', async () => {