add photo placeholder, mirrored camera capture, configurable footer, and student .url zip export

public/students.html

@@ -22,6 +22,7 @@
       <input type="text" id="studentSearch" class="search-input" placeholder="Поиск по имени..." style="flex:1;min-width:200px;max-width:340px;padding:10px 14px;font-size:.9rem">
       <select id="studentGroupFilter" class="search-input" style="padding:10px 14px"><option value="">Все группы</option></select>
       <button class="btn-link" onclick="exportStudentsCSV()">Экспорт CSV</button>
+      <button class="btn-link" onclick="exportStudentsUrls()">Экспорт URL</button>
     </div>
     <div class="list" id="studentList"></div>
     <div class="pager" id="pager"></div>
@@ -67,6 +68,7 @@
 
 <div class="toast" id="toast"></div>
 <script src="admin.js"></script>
+<script src="vendor/jszip.min.js"></script>
 <script>
 // --- Students ---
 let allStudents = [];
@@ -216,6 +218,15 @@ function exportStudentsCSV() {
   showToast(`Экспортировано: ${list.length}`);
 }
 
+async function exportStudentsUrls() {
+  const gid = document.getElementById('studentGroupFilter').value;
+  const list = gid ? allStudents.filter(s => String(s.group_id) === gid) : allStudents;
+  if (!list.length) { alert('Нет данных для экспорта'); return; }
+  const groupName = gid ? (allGroups.find(g => g.id == gid)?.name || 'group') : 'all';
+  await exportStudentUrlZip(list, `students_${groupName.replace(/[\\/:*?"<>|]/g, '_')}.zip`);
+  showToast(`Экспортировано: ${list.length}`);
+}
+
 // --- Batch attach ---
 async function openBatchAttach() {
   const sel = document.getElementById('attachGroup');