feat(teacher): stream Yuxi reasoning and answer previews

electron/coding-teacher/service.ts

@@ -36,6 +36,7 @@ import { prepareTeacherModel } from './model-runner';
 import { prepareCloudTeacher } from './cloud-runner';
 import { readTeacherSource } from './source-reader';
 import { applyTeacherReply, teacherReplyInstructions } from './reply';
+import { previewTeacherReply } from '../../shared/teacher-reply';
 import { subscribeWorksSquareSession } from '../services/works-square-session';
 
 export interface TeacherScope {
@@ -560,6 +561,7 @@ export class CodingTeacherService {
           ...(store instanceof TeacherConversationStore ? { archive: await store.history() } : {}),
           assertCurrent: () => this.assertAccount(account),
         };
+      let streamedResponse = '';
       const model = isCloud && access
         ? (this.options.prepareCloud ?? prepareCloudTeacher)(account, topic, input.requestId, access,
           (progress) => {
@@ -578,6 +580,16 @@ export class CodingTeacherService {
             else activities[index] = activity;
             topic.revision++;
             this.events.emit(key, structuredClone(topic));
+          }, update => {
+            this.assertAccount(account);
+            const current = topic.requests.find(request => request.id === input.requestId)!;
+            if (update.reasoning) current.reasoning = (current.reasoning ?? '') + update.reasoning;
+            if (update.response !== undefined) {
+              streamedResponse = update.response;
+              current.response = previewTeacherReply(streamedResponse);
+            }
+            topic.revision++;
+            this.events.emit(key, structuredClone(topic));
           })
         : await (this.options.prepareModel ?? prepareTeacherModel)(account, topic.definition,
           access,
@@ -671,10 +683,9 @@ export class CodingTeacherService {
               : '智能体回复失败，已保留本次问题与收到的内容。';
         } finally {
           // Keep received bytes inert even when an aborted runner resolves normally.
-          if (structuredReply && current.status !== 'completed' && structuredText)
-            current.unparsedResponse = structuredText;
+          if (structuredReply && current.status !== 'completed' && (structuredText || streamedResponse))
+            current.unparsedResponse = structuredText || streamedResponse;
           if (intent === 'suggestions' && current.status !== 'completed') {
-            current.response = '';
             delete current.suggestedQuestions;
           }
           topic.updatedAt = new Date().toISOString();