feat: integrate pixel teacher presence and resilient classroom preview

src/pages/Chat/TeacherCompanion.tsx

@@ -0,0 +1,44 @@
+import { ArrowUpRight, Loader2, X } from 'lucide-react';
+import type { Ref } from 'react';
+import teacherAvatar from '@/assets/consultations/teacher-pixel.png';
+import type { useTeacherCompanion } from './use-teacher-companion';
+
+type Companion = ReturnType<typeof useTeacherCompanion>;
+export function TeacherCompanion({ companion, open, onOpen, bubbleRef }: {
+  companion: Companion;
+  open: boolean;
+  onOpen(): void;
+  bubbleRef?: Ref<HTMLDivElement>;
+}) {
+  const { definition, invitation, welcome, loading, enabled, checking, error } = companion;
+  const name = definition?.name || '老师';
+  const viewConversation = () => { companion.dismiss(); onOpen(); };
+  const status = loading ? '正在连接老师…'
+    : checking ? '老师在看看你最近的进展…'
+    : error || (!enabled ? '老师暂未开放，仍可查看以往讨论' : open ? '我们慢慢聊，想到什么都可以说' : '点我聊聊，想到什么都可以说');
+  return (
+    <section className="teacher-companion no-drag" aria-label="老师陪伴" data-testid="teacher-companion">
+      <button type="button" className="teacher-companion-person" title={status} aria-label="老师" aria-expanded={open} aria-controls="coding-consultation-dock" onMouseDown={(event) => event.preventDefault()} onClick={onOpen}>
+        <span className="teacher-companion-avatar"><img src={teacherAvatar} alt="" />{invitation && <span className="teacher-companion-unread" aria-hidden="true" />}</span>
+        <span className="teacher-companion-name">{name}</span>
+        {checking && <Loader2 className="h-3 w-3 shrink-0 animate-spin text-muted-foreground motion-reduce:animate-none" aria-label="老师正在思考" />}
+      </button>
+      {(invitation || welcome) && <div ref={bubbleRef} className="teacher-companion-presence" data-testid="teacher-presence">
+        <div className="teacher-companion-bubble" data-testid="teacher-invitation" data-bubble-kind={invitation ? 'check-in' : 'welcome'}>
+          <div className="teacher-companion-bubble-heading">
+            <div className="teacher-companion-invitation-label">{name}</div>
+            <button type="button" className="teacher-companion-dismiss" aria-label="收起老师气泡" onClick={companion.dismiss}><X className="h-3.5 w-3.5" aria-hidden="true" /></button>
+          </div>
+          <p className="teacher-companion-message" role="status">{invitation?.response ?? welcome}</p>
+          <div className="teacher-companion-actions">
+            <button type="button" onClick={viewConversation}>{open ? '看看老师说的' : '和老师聊聊'} <ArrowUpRight aria-hidden="true" className="h-3 w-3" /></button>
+            <button type="button" onClick={companion.dismiss}>等会儿聊</button>
+          </div>
+        </div>
+        <button type="button" className="teacher-companion-speaker" aria-label="打开这条老师消息" onMouseDown={(event) => event.preventDefault()} onClick={viewConversation}>
+          <img src={teacherAvatar} alt="" />
+        </button>
+      </div>}
+    </section>
+  );
+}