Add optional audio response for students in homework submissions

- Course: add allowAudio toggle (per-course setting, off by default)
- HomeworkSubmission: add audioUrl field
- Student: AudioRecorder in homework form when allowAudio is enabled
- Student: show audio player in submission view and curator feedback view
- Curator: show student audio on submission detail page
- AudioRecorder: accept uploadUrl prop (reused for student/curator)
- API: /api/student/audio-upload route for S3 upload

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/components/admin/course-edit-form.tsx

@@ -14,6 +14,7 @@ interface Course {
   description: string | null;
   coverImage: string | null;
   published: boolean;
+  allowAudio: boolean;
   categoryId: string | null;
 }
 
@@ -24,6 +25,7 @@ interface Category {
 
 export function CourseEditForm({ course, categories = [] }: { course: Course; categories?: Category[] }) {
   const [published, setPublished] = useState(course.published);
+  const [allowAudio, setAllowAudio] = useState(course.allowAudio);
   const [coverImage, setCoverImage] = useState(course.coverImage ?? "");
   const [categoryId, setCategoryId] = useState(course.categoryId ?? "");
   const [uploading, setUploading] = useState(false);
@@ -45,6 +47,7 @@ export function CourseEditForm({ course, categories = [] }: { course: Course; ca
     e.preventDefault();
     const fd = new FormData(e.currentTarget);
     fd.set("published", String(published));
+    fd.set("allowAudio", String(allowAudio));
     fd.set("coverImage", coverImage);
     fd.set("categoryId", categoryId);
     startTransition(() => updateCourse(course.id, fd));
@@ -99,17 +102,33 @@ export function CourseEditForm({ course, categories = [] }: { course: Course; ca
           {uploading && <span className="text-sm text-slate-400">Загрузка...</span>}
         </div>
       </div>
-      <div className="flex items-center gap-2">
-        <button
-          type="button"
-          role="switch"
-          aria-checked={published}
-          onClick={() => setPublished(!published)}
-          className={`relative w-10 h-6 rounded-full transition-colors ${published ? "bg-green-500" : "bg-slate-300"}`}
-        >
-          <span className={`absolute top-1 left-1 w-4 h-4 bg-white rounded-full shadow transition-transform ${published ? "translate-x-4" : ""}`} />
-        </button>
-        <span className="text-sm text-slate-600">{published ? "Опубликован" : "Черновик"}</span>
+      <div className="space-y-2">
+        <div className="flex items-center gap-2">
+          <button
+            type="button"
+            role="switch"
+            aria-checked={published}
+            onClick={() => setPublished(!published)}
+            className={`relative w-10 h-6 rounded-full transition-colors ${published ? "bg-green-500" : "bg-slate-300"}`}
+          >
+            <span className={`absolute top-1 left-1 w-4 h-4 bg-white rounded-full shadow transition-transform ${published ? "translate-x-4" : ""}`} />
+          </button>
+          <span className="text-sm text-slate-600">{published ? "Опубликован" : "Черновик"}</span>
+        </div>
+        <div className="flex items-center gap-2">
+          <button
+            type="button"
+            role="switch"
+            aria-checked={allowAudio}
+            onClick={() => setAllowAudio(!allowAudio)}
+            className={`relative w-10 h-6 rounded-full transition-colors ${allowAudio ? "bg-blue-500" : "bg-slate-300"}`}
+          >
+            <span className={`absolute top-1 left-1 w-4 h-4 bg-white rounded-full shadow transition-transform ${allowAudio ? "translate-x-4" : ""}`} />
+          </button>
+          <span className="text-sm text-slate-600">
+            {allowAudio ? "🎤 Аудио-ответ в ДЗ включён" : "Аудио-ответ в ДЗ выключен"}
+          </span>
+        </div>
       </div>
       <div className="flex justify-between pt-2">
         <Button type="button" variant="destructive" onClick={handleDelete} disabled={pending}>