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 () => {

src/services/acp/agent/createSessionMethod.ts

@@ -270,11 +270,16 @@ async function createSession(
 
     this.sessions.set(sessionId, session)
 
-    // Stable v1 NewSessionResponse only defines sessionId/modes/configOptions.
-    // `models` is a draft/unstable field — omit it for v1 compliance.
+    // Return models even though SDK 0.19.2 marks it UNSTABLE. The schema does allow the field
+    // (NewSessionResponse.models?: SessionModelState | null), and standard clients (Cursor/Zed/
+    // VS Code ACP) rely on it to populate the model selector — omitting it forces
+    // supportsModelSelection=false on the client and the user can never switch models.
+    // The UNSTABLE marker only means "this field may change in a future schema version", not
+    // "agents MUST NOT return it". The previous "v1 compliance" omission was overzealous.
     return {
       sessionId,
       modes,
+      models,
       configOptions,
     }
   } finally {

src/services/acp/agent/sessionLifecycle.ts

@@ -79,6 +79,9 @@ async function getOrCreateSession(
       return {
         sessionId: params.sessionId,
         modes: existingSession.modes,
+        // Carry models over on reconnect so the client keeps its model selector
+        // populated (standard clients gate supportsModelSelection on this field).
+        models: existingSession.models,
         configOptions: existingSession.configOptions,
       }
     }
@@ -150,6 +153,8 @@ async function getOrCreateSession(
   return {
     sessionId: response.sessionId,
     modes: response.modes,
+    // createSession already returns models; pass it through. Same reason as above.
+    models: response.models,
     configOptions: response.configOptions,
   }
 }