feat: integrate pinned teacher discussion workspace

shared/coding-teacher.ts

@@ -1,3 +1,4 @@
+import type { TeacherDiscussion, TeacherDiscussionContent } from './teacher-discussion';
 import type { ManagedReasoningChoice } from './managed-model-capabilities';
 import type { PublicUsage } from './coding-conversation-contracts';
 
@@ -54,7 +55,24 @@ export type TeacherRequestStatus =
   | 'failed'
   | 'cancelled'
   | 'interrupted';
+export interface TeacherDiscussionContext {
+  toolId: string;
+  revision: number;
+  focusId?: string;
+  transition?: 'structure';
+}
+export interface TeacherDiscussionAction {
+  toolId: string;
+  revision: number;
+  action: 'enter' | 'pause' | 'finish' | 'resume' | 'keep-idea' | 'aside-idea' | 'first-idea' | 'back-ideas';
+  itemId?: string;
+}
 export interface TeacherRequest {
+  presentation?: 'discussion-v1';
+  discussionContext?: TeacherDiscussionContext;
+  discussionSnapshot?: TeacherDiscussionContent;
+  discussionError?: string;
+
   intent?: TeacherRequestIntent;
   sourceConversationId?: string;
   /** Digest of completed source text, retained for check-in deduplication across restarts. */
@@ -74,6 +92,7 @@ export interface TeacherRequest {
   usage?: PublicUsage;
 }
 export interface TeacherTopic {
+  discussion?: TeacherDiscussion;
   role?: ConsultationRole;
   revision: number;
   schemaVersion: 1;
@@ -94,6 +113,8 @@ export interface TeacherTopicList {
   lastSelectedTopicId: string | null;
 }
 export interface TeacherSend {
+  presentation?: 'discussion-v1';
+  discussion?: TeacherDiscussionContext;
   intent?: TeacherRequestIntent;
   sourceConversationId?: string;
   requestId: string;