Исправления расчёта цен и добавление функционала своей цены

- Исправлен расчёт цен: теперь учитывается метод (медиана/среднее) и период для каждого компонента
- Добавлены функции calculateMedian и calculateAverage
- Исправлен PreviewPrice для корректного предпросмотра с учётом настроек
- Сортировка по умолчанию изменена на популярность (desc)
- Добавлен раздел "Своя цена" в конфигуратор:
  - Ввод целевой цены с пропорциональным пересчётом всех позиций
  - Отображение скидки в процентах
  - Таблица скорректированных цен
  - Экспорт CSV со скидкой

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

web/templates/index.html

@@ -69,6 +69,66 @@
             <button onclick="exportCSV()" class="px-3 py-1 bg-gray-200 text-gray-700 rounded text-sm hover:bg-gray-300">Экспорт CSV</button>
         </div>
     </div>
+
+    <!-- Custom price section -->
+    <div id="custom-price-section" class="bg-white rounded-lg shadow p-4">
+        <h3 class="font-semibold mb-3">Своя цена</h3>
+        <div class="flex items-center gap-4 mb-4">
+            <div class="flex-1">
+                <label class="block text-sm text-gray-600 mb-1">Введите целевую цену</label>
+                <div class="flex items-center gap-2">
+                    <span class="text-gray-500">$</span>
+                    <input type="number" id="custom-price-input" step="0.01" min="0"
+                           placeholder="0.00"
+                           class="flex-1 px-3 py-2 border rounded focus:ring-2 focus:ring-blue-500"
+                           oninput="calculateCustomPrice()">
+                    <button onclick="clearCustomPrice()" class="px-3 py-2 text-gray-500 hover:text-gray-700">
+                        <svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                            <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M6 18L18 6M6 6l12 12"></path>
+                        </svg>
+                    </button>
+                </div>
+            </div>
+            <div id="discount-info" class="text-right hidden">
+                <div class="text-sm text-gray-600">Скидка</div>
+                <div class="text-2xl font-bold text-green-600" id="discount-percent">0%</div>
+            </div>
+        </div>
+
+        <!-- Adjusted prices table -->
+        <div id="adjusted-prices" class="hidden">
+            <div class="border-t pt-3">
+                <h4 class="text-sm font-medium text-gray-700 mb-2">Скорректированные цены</h4>
+                <div class="overflow-x-auto">
+                    <table class="w-full text-sm">
+                        <thead class="bg-gray-50">
+                            <tr>
+                                <th class="px-3 py-2 text-left text-xs font-medium text-gray-500 uppercase">Компонент</th>
+                                <th class="px-3 py-2 text-right text-xs font-medium text-gray-500 uppercase">Кол-во</th>
+                                <th class="px-3 py-2 text-right text-xs font-medium text-gray-500 uppercase">Было</th>
+                                <th class="px-3 py-2 text-right text-xs font-medium text-gray-500 uppercase">Стало</th>
+                                <th class="px-3 py-2 text-right text-xs font-medium text-gray-500 uppercase">Итого</th>
+                            </tr>
+                        </thead>
+                        <tbody id="adjusted-prices-body" class="divide-y"></tbody>
+                        <tfoot class="bg-gray-50 font-medium">
+                            <tr>
+                                <td class="px-3 py-2" colspan="2">Итого</td>
+                                <td class="px-3 py-2 text-right" id="adjusted-total-original">$0.00</td>
+                                <td class="px-3 py-2 text-right text-green-600" id="adjusted-total-new">$0.00</td>
+                                <td class="px-3 py-2 text-right text-green-600" id="adjusted-total-final">$0.00</td>
+                            </tr>
+                        </tfoot>
+                    </table>
+                </div>
+            </div>
+            <div class="mt-3 flex justify-end">
+                <button onclick="exportCSVWithCustomPrice()" class="px-4 py-2 bg-green-600 text-white rounded hover:bg-green-700">
+                    Экспорт CSV со скидкой
+                </button>
+            </div>
+        </div>
+    </div>
 </div>
 
 <!-- Autocomplete dropdown (shared) -->
@@ -643,6 +703,9 @@ function updateCartUI() {
     const total = cart.reduce((sum, item) => sum + (item.unit_price * item.quantity), 0);
     document.getElementById('cart-total').textContent = '$' + total.toLocaleString('en-US', {minimumFractionDigits: 2});
 
+    // Recalculate custom price section if active
+    calculateCustomPrice();
+
     if (cart.length === 0) {
         document.getElementById('cart-items').innerHTML =
             '<div class="text-gray-500 text-center py-2">Конфигурация пуста</div>';
@@ -752,6 +815,113 @@ async function exportCSV() {
     }
 }
 
+// Custom price functionality
+function calculateCustomPrice() {
+    const customPriceInput = document.getElementById('custom-price-input');
+    const customPrice = parseFloat(customPriceInput.value) || 0;
+
+    const originalTotal = cart.reduce((sum, item) => sum + (item.unit_price * item.quantity), 0);
+
+    if (customPrice <= 0 || cart.length === 0 || originalTotal <= 0) {
+        document.getElementById('adjusted-prices').classList.add('hidden');
+        document.getElementById('discount-info').classList.add('hidden');
+        return;
+    }
+
+    // Calculate discount percentage
+    const discountPercent = ((originalTotal - customPrice) / originalTotal) * 100;
+    const coefficient = customPrice / originalTotal;
+
+    // Show discount info
+    document.getElementById('discount-info').classList.remove('hidden');
+    document.getElementById('discount-percent').textContent = discountPercent.toFixed(1) + '%';
+
+    // Update discount color based on value
+    const discountEl = document.getElementById('discount-percent');
+    if (discountPercent > 0) {
+        discountEl.className = 'text-2xl font-bold text-green-600';
+    } else if (discountPercent < 0) {
+        discountEl.className = 'text-2xl font-bold text-red-600';
+    } else {
+        discountEl.className = 'text-2xl font-bold text-gray-600';
+    }
+
+    // Build adjusted prices table
+    let html = '';
+    let totalOriginal = 0;
+    let totalNew = 0;
+
+    cart.forEach(item => {
+        const originalPrice = item.unit_price;
+        const newPrice = originalPrice * coefficient;
+        const itemOriginalTotal = originalPrice * item.quantity;
+        const itemNewTotal = newPrice * item.quantity;
+
+        totalOriginal += itemOriginalTotal;
+        totalNew += itemNewTotal;
+
+        html += `
+            <tr>
+                <td class="px-3 py-2 font-mono">${escapeHtml(item.lot_name)}</td>
+                <td class="px-3 py-2 text-right">${item.quantity}</td>
+                <td class="px-3 py-2 text-right text-gray-500">$${originalPrice.toFixed(2)}</td>
+                <td class="px-3 py-2 text-right text-green-600">$${newPrice.toFixed(2)}</td>
+                <td class="px-3 py-2 text-right">$${itemNewTotal.toFixed(2)}</td>
+            </tr>
+        `;
+    });
+
+    document.getElementById('adjusted-prices-body').innerHTML = html;
+    document.getElementById('adjusted-total-original').textContent = '$' + totalOriginal.toFixed(2);
+    document.getElementById('adjusted-total-new').textContent = '$' + totalNew.toFixed(2);
+    document.getElementById('adjusted-total-final').textContent = '$' + totalNew.toFixed(2);
+    document.getElementById('adjusted-prices').classList.remove('hidden');
+}
+
+function clearCustomPrice() {
+    document.getElementById('custom-price-input').value = '';
+    document.getElementById('adjusted-prices').classList.add('hidden');
+    document.getElementById('discount-info').classList.add('hidden');
+}
+
+async function exportCSVWithCustomPrice() {
+    if (cart.length === 0) return;
+
+    const customPrice = parseFloat(document.getElementById('custom-price-input').value) || 0;
+    const originalTotal = cart.reduce((sum, item) => sum + (item.unit_price * item.quantity), 0);
+
+    if (customPrice <= 0 || originalTotal <= 0) {
+        showToast('Введите целевую цену', 'error');
+        return;
+    }
+
+    const coefficient = customPrice / originalTotal;
+
+    // Create adjusted cart
+    const adjustedCart = cart.map(item => ({
+        ...item,
+        unit_price: parseFloat((item.unit_price * coefficient).toFixed(2))
+    }));
+
+    try {
+        const resp = await fetch('/api/export/csv', {
+            method: 'POST',
+            headers: {'Content-Type': 'application/json'},
+            body: JSON.stringify({items: adjustedCart, name: configName})
+        });
+
+        const blob = await resp.blob();
+        const url = window.URL.createObjectURL(blob);
+        const a = document.createElement('a');
+        a.href = url;
+        a.download = (configName || 'config') + '.csv';
+        a.click();
+        window.URL.revokeObjectURL(url);
+    } catch(e) {
+        showToast('Ошибка экспорта', 'error');
+    }
+}
+
 </script>
 {{end}}