feat: integrate pixel teacher presence and resilient classroom preview

src/lib/classroom-layout.ts

@@ -0,0 +1,9 @@
+export const CLASSROOM_SIDEBAR_DEFAULT_WIDTH = 171;
+export const CLASSROOM_SIDEBAR_MIN_WIDTH = 128;
+export const CLASSROOM_SIDEBAR_MAX_WIDTH = 256;
+
+export function normalizeClassroomSidebarWidth(width: unknown): number {
+  return typeof width === 'number' && Number.isFinite(width)
+    ? Math.max(CLASSROOM_SIDEBAR_MIN_WIDTH, Math.min(CLASSROOM_SIDEBAR_MAX_WIDTH, Math.round(width)))
+    : CLASSROOM_SIDEBAR_DEFAULT_WIDTH;
+}

src/lib/coding-login-recovery.ts

@@ -0,0 +1,23 @@
+import type { AuthUser } from '@/stores/auth';
+
+export interface CodingLoginRecovery {
+  id: string;
+  account: string;
+  projectId: string;
+  conversationId: string | null;
+  work: boolean;
+}
+
+export function codingRecoveryAccount(user: AuthUser | null): string {
+  return user ? JSON.stringify([user.tenantId, user.userId, user.username]) : '';
+}
+
+export function readCodingLoginRecovery(value: unknown): CodingLoginRecovery | undefined {
+  if (!value || typeof value !== 'object') return;
+  const item = value as Partial<CodingLoginRecovery>;
+  if (typeof item.id !== 'string' || typeof item.account !== 'string' || !item.account
+    || typeof item.projectId !== 'string' || !item.projectId
+    || !(item.conversationId === null || typeof item.conversationId === 'string')
+    || typeof item.work !== 'boolean') return;
+  return item as CodingLoginRecovery;
+}

src/lib/coding-teacher.ts

@@ -2,6 +2,8 @@ import { hostApiFetch, createHostEventSource, ensureHostApiToken } from './host-
 import type {
   ConsultationRole,
   TeacherAvailability,
+  TeacherCheckInInput,
+  TeacherCheckInResult,
   TeacherDefinition,
   TeacherSend,
   TeacherTopic,
@@ -14,6 +16,11 @@ export function teacherTopicsPath(projectId: string, sourceId: string, role?: Co
     : `/api/coding/projects/${encodeURIComponent(projectId)}/conversations/${encodeURIComponent(sourceId)}/teacher-topics`;
 }
 export const teacherApi = {
+  checkIn: (projectId: string, input: TeacherCheckInInput) =>
+    hostApiFetch<TeacherCheckInResult>(`/api/coding/projects/${encodeURIComponent(projectId)}/teacher-check-in`, {
+      method: 'POST',
+      body: JSON.stringify(input),
+    }),
   config: (role: ConsultationRole = 'teacher') =>
     hostApiFetch<TeacherAvailability & { definition: TeacherDefinition | null }>(
       `/api/coding/${role}/config`
@@ -28,8 +35,8 @@ export const teacherApi = {
       method: 'POST',
       body: JSON.stringify({ draftRevision, sampleContext }),
     }),
-  read: (base: string, id: string) =>
-    hostApiFetch<TeacherTopic>(base + '/' + encodeURIComponent(id)),
+  read: (base: string, id: string, select = true) =>
+    hostApiFetch<TeacherTopic>(base + '/' + encodeURIComponent(id) + (select ? '' : '?select=false')),
   send: (base: string, id: string, input: TeacherSend) =>
     hostApiFetch<TeacherTopic>(base + '/' + encodeURIComponent(id) + '/messages', {
       method: 'POST',

src/lib/coding-work-preview.ts

@@ -0,0 +1,9 @@
+import { hostApiFetch } from './host-api';
+import type { WorkPreviewResult } from '../../shared/coding-work-preview';
+
+export function ensureWorkPreview(projectId: string, requestId: string, conversationId?: string | null): Promise<WorkPreviewResult> {
+  return hostApiFetch('/api/agent-browser/ensure-work', {
+    method: 'POST',
+    body: JSON.stringify({ project_id: projectId, request_id: requestId, conversation_id: conversationId }),
+  });
+}