Add duplicate and clear submissions functionality for challenge chains; implement corresponding dialogs and API endpoints, enhancing user experience and task management. Update localization for new features in English and Russian.

stubs/api/index.js

@@ -312,6 +312,84 @@ router.delete('/challenge/chain/:id', (req, res) => {
   respond(res, { success: true });
 });
 
+// POST /api/challenge/chain/:chainId/duplicate
+router.post('/challenge/chain/:chainId/duplicate', (req, res) => {
+  const chains = getChains();
+  const chainIndex = chains.findIndex(c => c.id === req.params.chainId);
+  
+  if (chainIndex === -1) {
+    return respondError(res, 'Chain not found', 404);
+  }
+  
+  const originalChain = chains[chainIndex];
+  const { name } = req.body;
+  
+  // Generate new name if not provided
+  const newName = name || `Копия - ${originalChain.name}`;
+  
+  // Create duplicate with same tasks but inactive
+  const duplicatedChain = {
+    _id: `chain_${Date.now()}`,
+    id: `chain_${Date.now()}`,
+    name: newName,
+    tasks: originalChain.tasks.map(task => ({
+      _id: task._id,
+      id: task.id,
+      title: task.title,
+      description: task.description,
+      createdAt: task.createdAt,
+      updatedAt: task.updatedAt
+    })),
+    isActive: false,
+    createdAt: new Date().toISOString(),
+    updatedAt: new Date().toISOString()
+  };
+  
+  chains.push(duplicatedChain);
+  
+  // Update stats
+  const stats = getStats();
+  stats.chains = chains.length;
+  
+  respond(res, duplicatedChain);
+});
+
+// DELETE /api/challenge/chain/:chainId/submissions
+router.delete('/challenge/chain/:chainId/submissions', (req, res) => {
+  const chains = getChains();
+  const submissions = getSubmissions();
+  
+  const chain = chains.find(c => c.id === req.params.chainId);
+  
+  if (!chain) {
+    return respondError(res, 'Chain not found', 404);
+  }
+  
+  // Get task IDs from chain
+  const taskIds = new Set(chain.tasks.map(t => t.id));
+  
+  // Count and remove submissions for tasks in this chain
+  let deletedCount = 0;
+  for (let i = submissions.length - 1; i >= 0; i--) {
+    const sub = submissions[i];
+    const taskId = typeof sub.task === 'object' ? sub.task.id : sub.task;
+    
+    if (taskIds.has(taskId)) {
+      submissions.splice(i, 1);
+      deletedCount++;
+    }
+  }
+  
+  // Update stats
+  const stats = getStats();
+  stats.submissions.total = Math.max(0, stats.submissions.total - deletedCount);
+  
+  respond(res, {
+    deletedCount: deletedCount,
+    chainId: chain.id
+  });
+});
+
 // ============= STATS =============
 
 // GET /api/challenge/stats